using Independentsoft.Sip;
using Independentsoft.Sip.Methods;
using Independentsoft.Sip.Responses;
using Independentsoft.Sip.Sdp;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Globalization;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace SipComponent
{
    /// <summary>
    /// <para>SipClientClass is an abstract class responsible for sending and receiving Sip messages and RTP packets,</para>
    /// <para>in accordance with the DMR Ais Specification</para>
    /// </summary>
    public abstract class SipClientClass
    {
        
        #region Private Fields

        private SipClient _sipClient;
        //private System.Timers.Timer _registrationTimer;

        private int _registrationInterval = 100; // 100s
        private RegistrationData _registrationData;
        private int _minPortNb = 25284;
        private int _maxPortNb = 25300;
        private int _audioBitRate = 16;
        private int _maxNbOfDialogs = 3;
        private int _secondsToWaitForSmsConfirmation = 3;
        private int _sipDomainPort;

        /// <summary>
        /// Nr de secunde cat este mentinut call-ul cand nu se transmite voce
        /// </summary>
        private int _hangTimeDuration = -1;
        private int _bufferMiliseconds;
        private string _localIPaddress;
        private Random _rand = new Random();
        private bool _sipClassClosed = false;
        private readonly bool _forSimoco = false;
        /// <summary>
        /// Gets or sets a value indicating if the Asterisk server confirms sms
        /// <para>Default value is false</para>
        /// </summary>
        protected bool _smsConfirmationFromServer = false;

        private Dictionary<string, Invite> _IDsentInviteDict = new Dictionary<string, Invite>();
        private Dictionary<string, Request> _IDreceivedInviteDict = new Dictionary<string, Request>();
        private Dictionary<string, Tuple<UdpClient, RTPSender2, RTPListener2, TimerWithTag<string>>> _IDdialogTuple = new Dictionary<string, Tuple<UdpClient, RTPSender2, RTPListener2, TimerWithTag<string>>>();
        private Dictionary<string, bool?> _smsSentDict = new Dictionary<string, bool?>();
        private Dictionary<string, Tuple<System.Timers.Timer, RegistrationStatus>> _sipID_regTimer_regStatus_Dict = 
            new Dictionary<string, Tuple<System.Timers.Timer, RegistrationStatus>>();
        private Dictionary<string, Tuple<byte[], TimerWithTag<string>>> _ID_pingBytest_timer_dict = new Dictionary<string,Tuple<byte[], TimerWithTag<string>>>();
        private Dictionary<string, string> _simocoID_emergencyStatusReport_dict = new Dictionary<string, string>();
        
        
        private object _lockerSmsSet = new object();

        private List<string> _IDsCalledByMeList = new List<string>();
        private List<string> _IDsCallingMeList = new List<string>();
        private List<string> _IDsInDialogWithList = new List<string>();
        private List<string> _IDsregisteredList = new List<string>();

        private static object _lockerRtpPort = new object();
        private object _lockerSipDialog = new object();
        private object _lockerCallingMe = new object();

        #region Protection against multiple sip messages sent (sometimes) by Asterisk

        string _previousEmergencySeqID = "";
        string _previousLocationSeqID = "";
        string _previousArsSeqID = "";
        string _previousSmsSeqID = "";

        #endregion

        #endregion

        #region Public Properties

        /// <summary>
        /// Gets or sets the minimum port number in the port range used for RTP voice transmission
        /// </summary>
        public int MinRtpPortNumber
        {
            get { return _minPortNb; }
            set
            {
                if (ValidRtpPort(value))
                {
                    _minPortNb = value;
                }
                else
                    throw new SipClassException(
                        string.Format("Port {0} is not a valid RTP port", value));
            }
        }

        /// <summary>
        /// Gets or sets the maximum port number in the port range used for RTP voice transmission
        /// </summary>
        public int MaxRtpPortNumber
        {
            get { return _maxPortNb; }
            set
            {
                if (ValidRtpPort(value))
                {
                    _maxPortNb = value;
                }
                else
                    throw new SipClassException(
                        string.Format("Port {0} is not a valid RTP port", value));
            }
        }

        /// <summary>
        /// Gets the sip ID
        /// </summary>
        public string UserName
        {
            get { return _sipClient.Username; }
        }

        /// <summary>
        /// <para>Gets or sets the maximum number of simultaneous dialogs that the SipClientClass accepts</para>
        /// <para>The default is 3</para>
        /// </summary>
        public int MaxNbOfDialogs
        {
            get { return _maxNbOfDialogs; }
            set
            {
                _maxNbOfDialogs = value;
            }
        }

        /// <summary>
        /// <para>Gets or sets the number of seconds the call is maintained when no voice is transmited</para>
        /// <para>Value is in seconds</para>
        /// <para>Default value is -1, call is maintained indefinitely</para>
        /// </summary>
        public int HangTimeDuration
        {
            get { return _hangTimeDuration; }
            set 
            {
                if (value > 0)
                    _hangTimeDuration = value;
            }
        }

        /// <summary>
        /// <para>Gets or sets a value indicating the nb of seconds to wait</para>
        /// <para>for a sms confirmation from sip server</para>
        /// <para>Default value is 3</para>
        /// </summary>
        public int SecondsToWaitForSmsConfirmation
        {
            get { return _secondsToWaitForSmsConfirmation; }
            set
            {
                if (value > 0 && value < 10)
                    _secondsToWaitForSmsConfirmation = value;
            }
        }

        /// <summary>
        /// Audio BitRate, default value is 16
        /// </summary>
        public int AudioBitrate
        {
            get { return _audioBitRate; }
            set { _audioBitRate = value; }
        }

        /// <summary>
        /// Gets a readonly collection of sip ids that you sent Invite for
        /// </summary>
        public ReadOnlyCollection<string> SipIDsCalledByMe
        {
            get { return new ReadOnlyCollection<string>(_IDsCalledByMeList); }
        }

        /// <summary>
        /// Gets a readonly collection of sip ids that sent you Invite's
        /// </summary>
        public ReadOnlyCollection<string> SipIDsCallingMe
        {
            get { return new ReadOnlyCollection<string>(_IDsCallingMeList); }
        }

        /// <summary>
        /// Gets a readonly collection of sip ids that you are in dialog with
        /// </summary>
        public ReadOnlyCollection<string> SipIDsInDialogWith
        {
            get { return new ReadOnlyCollection<string>(_IDsInDialogWithList); }
        }

        /// <summary>
        /// Gets a readonly collection of sip ids that you are registered to 
        /// <para>This means your sip id and the group ids that you are listening to</para>
        /// </summary>
        public ReadOnlyCollection<string> SipIDsRegisteredTo
        {
            get
            {
                return new ReadOnlyCollection<string>(_IDsregisteredList);
            }
        }

        #endregion

        // constructor
        /// <summary>
        /// Constructor for the SipClientClass
        /// </summary>
        /// <param name="sipDomain">domain name, name or IP address of sip server</param>
        /// <param name="sipDomainPort">port number of the sip server</param>
        /// <param name="localSipPort">port number of the local computer used for sip protocol</param>
        /// <param name="userName">user name on the sip server</param>
        /// <param name="password">password on the sip server</param>
        /// <param name="registrationInterval">interval to send sip registration requests. Value is in seconds</param>
        /// <param name="bufferMiliseconds">Miliseconds for the buffer that stores the received voice packets</param>
        /// <param name="requestTimeout">Number of ms to wait before the sip request times out</param>
        /// <param name="localIPAddress">Local Ip adress. If not specified, the class will search for a local ip on the same network with the sip server ip</param>
        /// <param name="simoco">True if the class is used for sip communication with Simoco ais-gateway</param>
        internal SipClientClass(string sipDomain, int sipDomainPort, int localSipPort, string userName, string password, int registrationInterval, int bufferMiliseconds,
            int requestTimeout, string localIPAddress = null, bool simoco = false)
        {
            _forSimoco = simoco;

            if (localIPAddress == null)
            //_localIPaddress = GetLocalAddresOnNetworkWith(IPAddress.Parse(sipDomain));
            {
                _localIPaddress = BestLocalEndPoint(new IPEndPoint(IPAddress.Parse(sipDomain), sipDomainPort)).Address.ToString();
#if DEBUG
                Console.WriteLine("Local IP selected: " + _localIPaddress);
#endif
            }
            else
                _localIPaddress = localIPAddress;
            _sipDomainPort = sipDomainPort;
            _sipClient = CreateSipClientClass(sipDomain, _sipDomainPort, _localIPaddress, localSipPort, userName, password, requestTimeout);
            _bufferMiliseconds = bufferMiliseconds;
            // Registration Timer
            _registrationInterval = registrationInterval;
            _registrationData = new RegistrationData(userName, _registrationInterval + 2);
            System.Timers.Timer registrationTimer = new System.Timers.Timer();
            // Set up the registration timer
            registrationTimer.Interval = _registrationInterval * 1000;
            registrationTimer.Elapsed += _registrationTimer_Elapsed;
            _sipID_regTimer_regStatus_Dict.Add(userName, 
                new Tuple<System.Timers.Timer,RegistrationStatus>(registrationTimer, RegistrationStatus.RegistrationNotStarted
));
            _IDsregisteredList.Add(userName);
            StartRegistrationTimer();
        }

        #region Public Methods

        /// <summary>
        /// Sends a Sip Invite command to an user
        /// </summary>
        /// <param name="idToInvite">The sip id of the user</param>
        /// <param name="typeOfCall">Type of call: full duplex or half duplex</param>
        protected void Invite(string idToInvite, TypeOfCall typeOfCall)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToInvite == null)
                throw new ArgumentNullException("idToInvite");
            if (_forSimoco && typeOfCall != TypeOfCall.HALF_DUPLEX)
                throw new SipClassException("Cannot make a full duplex call with Simoco");
            lock (_lockerSipDialog)
            {
                if (!_IDsentInviteDict.ContainsKey(idToInvite) && !_IDreceivedInviteDict.ContainsKey(idToInvite)
                    && !_IDdialogTuple.ContainsKey(idToInvite))
                {
                    SendSipInvite(idToInvite, typeOfCall);
                }
            }
        }

        /// <summary>
        /// Sends a Sip Invite command to a Simoco Group
        /// </summary>
        /// <param name="groupIDtoInvite">The sip id of the group</param>
        protected void InviteGroup(string groupIDtoInvite)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (groupIDtoInvite == null)
                throw new ArgumentNullException("groupIDtoInvite");
            // Check if registered to the group id
            lock (_lockerSipDialog)
            {
                if (!_IDdialogTuple.ContainsKey(groupIDtoInvite))
                    SendSipInvite(groupIDtoInvite, TypeOfCall.HALF_DUPLEX, true);
            }
        }

        /// <summary>
        /// Cancels an Invite sent to an user
        /// </summary>
        /// <param name="idToCancel">The sip id of the user</param>
        public void CancelInvite(string idToCancel)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            Task t = null;
            CancelInvite_private(idToCancel, out t);
        }

        private void CancelInvite_private(string idToCancel, out Task sendingCancelTask)
        {
            sendingCancelTask = null;
            lock (_lockerSipDialog)
            {
                if (_IDsentInviteDict.ContainsKey(idToCancel))
                {
                    sendingCancelTask = SendCancelRequest(idToCancel, sendingCancelTask);
                }
            }
            // fire event
            OnInviteSentCanceled(new SipEventArgs(idToCancel));
        }

        private Task SendCancelRequest(string idToCancel, Task sendingCancelTask)
        {
            // Send Cancel Request
            if (_IDsentInviteDict.ContainsKey(idToCancel))
            {

                Dialog d = _sipClient.Dialogs.FirstOrDefault((dialog) =>
                {
                    return dialog.CallID == _IDsentInviteDict[idToCancel].CallID;
                });
                if (d != null)
                {
                    //Send Cancel Request
                    sendingCancelTask = Task.Factory.StartNew((dialogObj) =>
                    {
                        try
                        {
                            _sipClient.Cancel((Dialog)dialogObj);
                        }
                        catch (Independentsoft.Sip.TimeoutException)
                        {
                            ;
                        // Don't to anything if timeout exception
                        // the receiver did not answer;
                        }   
                    }, d);
                }
                // Remove from dict
                _IDsentInviteDict.Remove(idToCancel);
                _IDsCalledByMeList.Remove(idToCancel);
            }
            return sendingCancelTask;
        }

        /// <summary>
        /// Accepts an Invite from an user
        /// </summary>
        /// <param name="callingSipID">The sip ID of the user</param>
        public void AcceptInvite(string callingSipID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            bool fireEvent = false;
            bool success = true;
            bool sendBusy = true;
            string failedMsg = "";
            lock (_lockerCallingMe)
            {
                if (_IDreceivedInviteDict.ContainsKey(callingSipID))
                {
                    fireEvent = true;
                    Request receivedInvite = _IDreceivedInviteDict[callingSipID];
                    // Answer the call
                    OK okResponseToInvite = new OK();
                    // TO DO - fara asta (adaugare header Contact) nu merge Simoco (Zoiper-ul e ok);
                    okResponseToInvite.Header[StandardHeader.Contact] = "<sip:" + _sipClient.Username + "@" + _sipClient.LocalIPEndPoint.ToString() + ";transport=udp>";
                    // Generate SDP
                    // Check if invite is full or half duplex
                    TypeOfCall typeOfCall = GetTypeOfCall(receivedInvite);
                    // Check if it was group invite
                    bool isGroupCall = false;
                    if (receivedInvite.Header.ContainsKey("Ais-Reach"))
                        if (receivedInvite.Header["Ais-Reach"] == "group")
                            isGroupCall = true;


                    int port = ReturnAvailablePort();
                    okResponseToInvite.SessionDescription = CreateSDP(port, typeOfCall);
                    // Try to create the dialog
                    try
                    {
                        CreatingDialog(callingSipID, isGroupCall, receivedInvite.SessionDescription, typeOfCall, port, false);
                        // Trimit Ok
                        _sipClient.SendResponse(okResponseToInvite, receivedInvite);
                    }
                    catch (SipClassException)
                    {
                        // TO DO - verify this

                        // This is the strange case of "Already in dialog with....."
                        // generated by Asterisk sending multiple invite request
                        // I should ignore the isssue (not send busy, not fire event)
                        sendBusy = false;
                        fireEvent = false;
                        success = false;
                    }
                    catch (Exception ex)
                    {
                        // Nu am reusit sa creez dialogul
                        bool wasGroupCall;
                        ClosingDialog(callingSipID, _sipClient.Username, out wasGroupCall);
                        failedMsg = ex.Message;
                        success = false;
                    }
                    finally
                    {
                        // Remove from dictionary
                        _IDreceivedInviteDict.Remove(callingSipID);
                        _IDsCallingMeList.Remove(callingSipID);
                    }
                    
                    if (!success)
                    {
                        if (sendBusy)
                        {
                            // Trimit Busy Here
                            Task.Factory.StartNew(() => { _sipClient.SendResponseBusyHere(receivedInvite); });
                        }
                    }
                    
                }
            }
            // Fire event
            if (fireEvent)
            {
                if (!success)
                    OnError(new ErrorEventArgs(_sipClient.Username, callingSipID, failedMsg));
            }
        }

        /// <summary>
        /// Closes a sip dialog (voice session) with an user
        /// </summary>
        /// <param name="idToClose">The sip id of the user</param>
        /// <returns>true if the dialog was closed, else false</returns>
        public bool Close(string idToClose)
        {
            bool dialogClosed = false;
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToClose != null)
            {
                Task t = null;
                dialogClosed = Close_private(idToClose, out t, DialogClosedReason.NormalClosing);
            }
            else throw new ArgumentNullException("idToClose");
            return dialogClosed;
        }

        private bool Close_private(string idToClose, out Task sendingByeTask, DialogClosedReason reason)
        {
            bool fireEvent = false;
            sendingByeTask = null;
            bool wasGroupCall = false;
            lock (_lockerSipDialog)
            {
                Dialog dialogToClose = _sipClient.GetDialogWith(idToClose);
                if (dialogToClose != null)
                {
                    if (ClosingDialog(idToClose, _sipClient.Username, out wasGroupCall))
                    {
                        fireEvent = true;
                        sendingByeTask = Task.Factory.StartNew((dialogToCloseObj) =>
                        {
                            try
                            {
                                _sipClient.Bye((Dialog)dialogToCloseObj);
                            }
                            catch (Exception ex)
                            {
                                // To do
                                // For now, do nothing
                                ;
                            }
                        }, dialogToClose);
                    }
                }
            }
            // FireEvent
            if (fireEvent)
                OnDialogClosed(new DialogClosedEventArgs(
                    idToClose, _sipClient.Username, wasGroupCall, reason));
            return fireEvent;
        }

        /// <summary>
        /// Declines a received Invite from an user
        /// </summary>
        /// <param name="idToDeclineCall">The sip ID of the user</param>
        public void Decline(string idToDeclineCall)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToDeclineCall != null)
            {
                Task t = null;
                Decline_private(idToDeclineCall, out t);
            }
            else
                throw new ArgumentNullException("idToDeclineCall");
        }

        private void Decline_private(string idToDeclineCall, out Task sendBusyTask)
        {
            bool fireEvent = false;
            sendBusyTask = null;
            lock (_lockerCallingMe)
            {
                if (_IDreceivedInviteDict.ContainsKey(idToDeclineCall))
                {
                    fireEvent = true;
                    Request inviteReq = _IDreceivedInviteDict[idToDeclineCall];
                    // Remove from dictionary
                    _IDreceivedInviteDict.Remove(idToDeclineCall);
                    _IDsCallingMeList.Remove(idToDeclineCall);
                    // Send busy here
                    sendBusyTask = Task.Factory.StartNew(() =>
                    {
                        _sipClient.SendResponseBusyHere(inviteReq);
                    });
                }
            }
            // Fire event
            if (fireEvent)
                OnInviteReceivedDeclined(new SipEventArgs(idToDeclineCall));
        }

        /// <summary>
        /// Accepts a PTT Request from an user
        /// </summary>
        /// <param name="idToGrantPTT">The sip ID of the user</param>
        protected void GrantPTT(string idToGrantPTT)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToGrantPTT != null)
            {
                lock (_lockerSipDialog)
                {
                    if (_IDdialogTuple.ContainsKey(idToGrantPTT))
                    {
                        RTPListener2 rtpListener = _IDdialogTuple[idToGrantPTT].Item3;
                        if (rtpListener.ReceivedTSNStatus == TSNstatus.Requesting)
                        {
                            rtpListener.SetRequestedTSNstatus(new TSNinfo(rtpListener.LastRequestedTSNReceived) { Status = TSNstatus.Granted });
                            _IDdialogTuple[idToGrantPTT].Item2.SendPTTGrant(rtpListener.LastRequestedTSNReceived);
                        }
                    }
                }
            }
            else
                throw new ArgumentNullException("idToGrantPTT"); 
        }

        /// <summary>
        /// Method used to check if you received PTT Grant from the specified user
        /// </summary>
        /// <param name="sipIDinDialogWith">The sip id of the user</param>
        /// <returns>True if you received ptt Grant, else false</returns>
        protected bool PTTGrantReceived(string sipIDinDialogWith)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (sipIDinDialogWith != null)
            {
                if (_IDdialogTuple.ContainsKey(sipIDinDialogWith))
                    return _IDdialogTuple[sipIDinDialogWith].Item2.SentTSNstatus == TSNstatus.Granted;
                else
                    return false;
            }
            else
                throw new ArgumentNullException("idInDialogWith");
        }

        /// <summary>
        /// Method used to send Deny when you receive a PTT Request 
        /// </summary>
        /// <param name="idToDenyPTT">The sip ID sending PTT Request</param>
        protected void DenyPTT(string idToDenyPTT)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToDenyPTT != null)
            {
                lock (_lockerSipDialog)
                {
                    if (_IDdialogTuple.ContainsKey(idToDenyPTT))
                    {
                        RTPListener2 rtpListener = _IDdialogTuple[idToDenyPTT].Item3;
                        if (rtpListener.ReceivedTSNStatus == TSNstatus.Requesting)
                        {
                            rtpListener.SetRequestedTSNstatus(new TSNinfo(rtpListener.LastRequestedTSNReceived) { Status = TSNstatus.Denied });
                            _IDdialogTuple[idToDenyPTT].Item2.SendPTTDeny(rtpListener.LastRequestedTSNReceived);
                        }
                    }
                }
            }
            else 
                throw new ArgumentNullException("idToDenyPTT");
        }

        /// <summary>
        /// Method used to start sending PTT Requests to a sip id
        /// </summary>
        /// <param name="sipID">The sip ID to send PTT Requests</param>
        protected void RequestPTT(string sipID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            byte tsn = GenerateNewTSN();
            lock (_lockerSipDialog)
            {
                if (_IDdialogTuple.ContainsKey(sipID))
                {
                    // Send PTT request
                    RTPSender2 rtpSender = _IDdialogTuple[sipID].Item2;
                    rtpSender.StartSendingPTTrequests(tsn);
                }
            }
        }

        /// <summary>
        /// Method used to send End PTT to a sip id
        /// </summary>
        /// <param name="sipID">The sip id to send End PTT</param>
        protected void EndPTT(string sipID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            lock (_lockerSipDialog)
            {
                if (_IDdialogTuple.ContainsKey(sipID))
                {
                    if (_IDdialogTuple[sipID].Item2.SentTSNstatus == TSNstatus.Granted)
                    {
                        // Sent PTT End
                        RTPSender2 rtpSender = _IDdialogTuple[sipID].Item2;
                        for (int i = 0; i < DMR.T_numend; i++)
                        {
                            rtpSender.SendPTTEnd();
                            System.Threading.Thread.Sleep(DMR.T_end);
                        }
                        // Restart the hangTime timer
                        TimerWithTag<string> timer = _IDdialogTuple[sipID].Item4;
                        if (timer != null)
                        {
                            timer.Start();
                        }
                    }
                }
            }
        }

        /// <summary>
        /// Sends a voice buffer in a specified format to the user in dialog with
        /// </summary>
        /// <param name="idToSendVoice">The sip ID of the user</param>
        /// <param name="audioBuffer">The audio buffer</param>
        /// <param name="bufferLength">The length of the buffer</param>
        /// <param name="format">The audio format of the buffer</param>
        public virtual void SendAudio(string idToSendVoice, byte[] audioBuffer, int bufferLength, AudioFormat format)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            lock (_lockerSipDialog)
            {
                if (_IDdialogTuple.ContainsKey(idToSendVoice))
                {
                    _IDdialogTuple[idToSendVoice].Item2.SendAudio(audioBuffer, bufferLength, format);
                }
            }
        }

        /// <summary>
        /// Method used to send a Gps Request to a Simoco radio
        /// </summary>
        /// <param name="idToRequestGPS">The simoco ID to send Gps Request</param>
        public void SendSimocoGpsRequest(string idToRequestGPS)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToRequestGPS != null)
            {
                if (_forSimoco)
                {
                    // Send Gps request for Simoco
                    Message gpsRequest = GenerateSipGpsRequestMessage(idToRequestGPS, UserName, _sipClient.Domain, _sipDomainPort);
                    Task.Factory.StartNew(() => 
                    {
                        try
                        {
                            _sipClient.SendRequest(gpsRequest);
                        }
                        catch (Exception)
                        {
                            // Probably timeout exception
                            ;
                        }
                    });
                }
                else
                    throw new SipClassException("To use SendSimocoGpsRequest() set Simoco value in constructor");
            }
            else 
                throw new ArgumentNullException("idToRequestGPS");
        }

        /// <summary>
        /// Method used to send Gps Request to a Linx device
        /// </summary>
        /// <param name="idToRequestGps">The sip id to send the gps request</param>
        /// <param name="seqID">The sequence id</param>
        protected void SendLinxGpsRequest(string idToRequestGps, string seqID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (!_forSimoco)
            {
                if (idToRequestGps != null)
                {
                    // Send Gps request for Linx
                    // [#msgLen]#seqID#154#
                    string cmdText = string.Format("#{0}#154#", seqID);
                    string cmd = AddMsgLenForMBus(cmdText);
                    Message pollRequestForLinx = SipMessageGenerator.Generate(idToRequestGps, UserName, _sipClient.Domain, _sipDomainPort, cmd);
                    pollRequestForLinx.Header.Add("Ais-Service", "mbus");
                    Task.Factory.StartNew(() =>
                    {
                        try
                        {
                            _sipClient.SendRequest(pollRequestForLinx);
                        }
                        catch (Exception)
                        {
                            ; // Probably timeout exception, do not do anything
                        }
                    });
                }
                else
                    throw new ArgumentNullException("idToRequestGps");
            }
            else
                throw new SipClassException("SendLinxGpsRequest does not work for Simoco");
        }

        /// <summary>
        /// Method used to send a Ping command to a Simoco radio
        /// </summary>
        /// <param name="idToSendPing">The Simoco ID of the radio</param>
        protected void SendSimocoPing(string idToSendPing)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToSendPing != null)
            {
                if (_forSimoco)
                {
                    Byte[] bytesToSend = new byte[3];
                    _rand.NextBytes(bytesToSend);
                    if (!_ID_pingBytest_timer_dict.ContainsKey(idToSendPing))
                    {
                        TimerWithTag<string> pingTimer = new TimerWithTag<string>(2000, idToSendPing);

                        pingTimer.Elapsed += pingTimer_Elapsed;
                        pingTimer.AutoReset = false;
                        pingTimer.Start();
                        _ID_pingBytest_timer_dict.Add(idToSendPing, new Tuple<byte[], TimerWithTag<string>>(bytesToSend, pingTimer));
                        
                        // Send ping to simoco

                        Message pingMessage = GenerateSipPingMessage(idToSendPing, UserName, _sipClient.Domain, _sipDomainPort, bytesToSend);
                        Task.Factory.StartNew(() => 
                        {
                            try
                            {
                                RequestResponse rr = _sipClient.SendRequest(pingMessage);
                            }
                            catch (Exception)
                            {
                                // probably timeout exception
                                // don't do anything
                                ;
                            }

                        });
                    }
                }
                else
                    throw new ApplicationException("Cannot send ping command if simoco parameter was not specified in constructor");
            }
            else
                throw new ArgumentNullException("idToSendPing");
        }

        /// <summary>
        /// Method used to send a Ping command to an Excera radio
        /// </summary>
        /// <param name="idToSendPing">The Excera ID of the radio</param>
        protected void SendExceraPing(string idToSendPing)
        {
            Message ping = GenerateExceraRadioCheckMessage(idToSendPing, UserName, _sipClient.Domain, _sipDomainPort);
            Task.Factory.StartNew(() => 
            {
                try
                {
                    RequestResponse rr = _sipClient.SendRequest(ping);
                    if (rr.Response.StatusCode == 200) // I received OK
                    {
                        OnSimocoPingResponseReceived(new SipEventArgs(idToSendPing));
                    }
                    else
                    {
                        OnSimocoPingRequestFailed(new SipEventArgs(idToSendPing));
                    }
                }
                catch (Independentsoft.Sip.TimeoutException tEx)
                {
                    throw new SipClassException("Timeout exception, could not reach the Excera repeater", tEx);
                }
                catch (Exception ex)
                {
                    throw new SipClassException("Error when trying to send ping to excera", ex);
                }
            });
        }

        void pingTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            string id = ((TimerWithTag<string>)sender).Tag;
            if (_ID_pingBytest_timer_dict.ContainsKey(id))
            {
                _ID_pingBytest_timer_dict.Remove(id);
                // Fire event
                OnSimocoPingRequestFailed(new SipEventArgs(id));
            }
        }

        /// <summary>
        /// Method used to acknowledge a Simoco emergency status report
        /// </summary>
        /// <param name="simocoID">The id of the Simoco radio</param>
        protected void AcknowledgeSimocoEmergencyStatusReport(string simocoID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (!_forSimoco)
                throw new ApplicationException("AcknowledgeSimocoEmergencyStatusReport() is used just for Simoco");
            if (simocoID != null)
            {
                if (_simocoID_emergencyStatusReport_dict.ContainsKey(simocoID))
                {
                    Message ackMessage = GenerateSimocoAckForDeviceStatusReport(simocoID, UserName, _sipClient.Domain, _sipDomainPort,
                        _simocoID_emergencyStatusReport_dict[simocoID]);
                    Task.Factory.StartNew(() =>
                    {
                        try
                        {
                            _sipClient.SendRequest(ackMessage);
                        }
                        catch (Exception)
                        {
                            // don't do anything
                        }
                    });
                }
            }
            else throw new ArgumentNullException("simocoID");
        }

        /// <summary>
        /// Method used to acknowledge an emergency alarm sent by a Linx device
        /// </summary>
        /// <param name="linxID">The sip id of the Linx device</param>
        protected void AcknowledgeLinxEmergencyAlarm(string linxID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (_forSimoco)
                throw new ApplicationException("AcknowledgeLinxEmergencyAlarm cannot be used for Simoco");
            if (linxID != null)
            {
                // Send [#msgLen]#seqID#238#
                string textToSend = string.Format("#{0}#238#", _rand.Next().ToString());
                string cmdToSend = AddMsgLenForMBus(textToSend);
                Message sipMessage = SipMessageGenerator.Generate(linxID, UserName, _sipClient.Domain, _sipDomainPort, cmdToSend);
                Task.Factory.StartNew(() => 
                {
                    try
                    {
                        _sipClient.SendRequest(sipMessage);
                    }
                    catch (Exception)
                    {
                        // Do nothing
                    }
                });
            }
            else
                throw new ArgumentNullException("linxID");
        }

        /// <summary>
        /// Just for testing purposes
        /// </summary>
        public void SendLocation(string idToSendLocation, double latitude, double longitude, double speed)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (_forSimoco)
                throw new ApplicationException("Cannot send location to Simoco Ais-Gateway");
            if (idToSendLocation != null)
            {
                // #msgLen#seqID#Opcode#remoteRadioId#locationTime#speed#latitude# longitude#
                // #seqID#Opcode#remoteRadioId#locationTime#speed#latitude# longitude#
                string textToSend = string.Format("#12345#131#{0}#{1}#{2}#{3}#{4}#",
                    UserName, DateTimeToUnixTime(DateTime.UtcNow).ToString(CultureInfo.InvariantCulture), 
                    speed.ToString(CultureInfo.InvariantCulture), 
                    latitude.ToString(CultureInfo.InvariantCulture), 
                    longitude.ToString(CultureInfo.InvariantCulture));
                string cmd = AddMsgLenForMBus(textToSend);
                Message gpsMessage = SipMessageGenerator.Generate(idToSendLocation, UserName, _sipClient.Domain, _sipDomainPort, cmd);
                gpsMessage.Header.Add("Ais-Service", "mbus");

                Task.Factory.StartNew(() => 
                {
                    try
                    {
                        _sipClient.SendRequest(gpsMessage);
                    }
                    catch (Exception)
                    {
                        ;
                        // timout expired - do nothing
                    }
                });
            }
            else 
                throw new ArgumentNullException("idToSendLocation");

        }

        /// <summary>
        /// Method used to send an sms to sip id
        /// <para>This method does not block the calling thread while waiting for the confirmation</para>
        /// </summary>
        /// <param name="idToSendSMS">The sip id where to send the sms</param>
        /// <param name="text">The sms text</param>
        /// <param name="isGroupSms">True if the sms is a sip group sms</param>
        /// <returns>True if the sms was received, else returns false</returns>
        public async Task<bool> SendSmsAsync(string idToSendSMS, string text, bool isGroupSms = false)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (idToSendSMS != null && text != null)
            {
                bool sendSipMessage = true;
                string unconfirmedSmsKey = null;
                if (_smsConfirmationFromServer)
                {
                    unconfirmedSmsKey = idToSendSMS + text.GetHashCode();
                    // Add smsKey to unconfirmed sms set
                    lock (_lockerSmsSet)
                    {
                        if (!_smsSentDict.ContainsKey(unconfirmedSmsKey))
                        {
                            _smsSentDict.Add(unconfirmedSmsKey, null);
                        }
                        else
                        {
                            // Already the same msg to the same id in the dict
                            // Will not send sip message, just wait for the later to be confirmed
                            sendSipMessage = false;
                        }
                    }
                }
                if (sendSipMessage)
                {
                    // Create a new thread on which:
                    // 1. Send sip message
                    // 2. Wait for confirmation that the mess reach the server
                    // 3. Wait for confirmation that the mess reach the destination id
                    return await Task.Factory.StartNew(() =>
                    {
                        // Send Sms using sip library
                        try
                        {
                            //RequestResponse rr = _sipClient.SendMessage(
                            //    string.Format("sip:{0}@{1}", _sipClient.Username, _sipClient.Domain),
                            //    string.Format("sip:{0}@{1}", idToSendSMS, _sipClient.Domain),
                            //    text);
                            Message sipMsg = SipMessageGenerator.Generate(idToSendSMS, _sipClient.Username, _sipClient.Domain, 
                                _sipDomainPort, text, isGroupSms);
                            RequestResponse rr = _sipClient.SendRequest(sipMsg);
                            // Message got to the sip server
                            if (rr.Response.Description == "OK" || rr.Response.Description == "Accepted")
                            {
                                if (unconfirmedSmsKey != null)
                                {
                                    if (SmsConfirmedBySipServer(unconfirmedSmsKey))
                                        return true;
                                    else
                                        return false;
                                }
                                else
                                    return true;
                            }
                            else // Sip server did not accept the message
                                return false;
                        }
                        catch (Exception)
                        {
                            // Probably timeout exception, msg didn't reach the sip server
                            return false;
                        }

                    });
                }
                else
                    return await Task.Factory.StartNew<bool>(SmsConfirmedBySipServer, unconfirmedSmsKey);
                
            }
            else if (idToSendSMS == null)
                throw new ArgumentNullException("idToSendSMS");
            else
                throw new ArgumentNullException("text");
        }

        /*

        /// <summary>
        /// Generates a Sip message using the specified parameters
        /// </summary>
        /// <param name="destinationID"></param>
        /// <param name="senderID"></param>
        /// <param name="sipServer"></param>
        /// <param name="sipServerPort"></param>
        /// <param name="text"></param>
        /// <param name="simoco"></param>
        /// <returns></returns>
        protected virtual Message GenerateSipMessage(string destinationID, string senderID, string sipServer, 
            int sipServerPort, string text, bool simoco = false)
        {
            Message sipMessage = new Message();
            sipMessage.Uri = "sip:" + destinationID + "@" + sipServer + ":" + sipServerPort;
            sipMessage.From = new ContactInfo(string.Format("sip:{0}@{1}", senderID, sipServer));
            sipMessage.To = new ContactInfo(string.Format("sip:{0}@{1}", destinationID, sipServer));
            if (simoco)
            {
                sipMessage.ContentType = "application/octet-stream";
                // Softul de pe AIS are nevoie de punct si virgula (;) dupa short-data
                sipMessage.Header.Add("Ais-Service", "short-data;");
                sipMessage.Header.Add("Ais-Options", "service-attributes; coding=unicode-16");
                sipMessage.Header.Add("Content-Transfer-Encoding", "base64");
                sipMessage.Body = Convert.ToBase64String(Encoding.BigEndianUnicode.GetBytes(text));
            }
            else
            {
                sipMessage.ContentType = "text/plain;charset=UTF-8";
                sipMessage.Body = text;
            }
            return sipMessage;
        }


        */

        private Message GenerateSipGpsMessage(string destinationID, string senderID, string sipServer,
            int sipServerPort, string gpsText)
        {
            Message sipGpsMessage = new Message();
            sipGpsMessage.Uri = "sip:" + destinationID + "@" + sipServer + ":" + sipServerPort;
            sipGpsMessage.From = new ContactInfo(string.Format("sip:{0}@{1}", senderID, sipServer));
            sipGpsMessage.To = new ContactInfo(string.Format("sip:{0}@{1}", destinationID, sipServer));

            sipGpsMessage.ContentType = "text/plain;charset=UTF-8";
            //sipGpsMessage.ContentType = "application/octet-stream";
            sipGpsMessage.Header[StandardHeader.ContentEncoding] = "base64";
            sipGpsMessage.Header.Add("Ais-Service", "short-data");
            sipGpsMessage.Header.Add("Ais-Options", "service-attributes; coding=nmea");
            sipGpsMessage.Body = gpsText;

            return sipGpsMessage;
        }

        private Message GenerateSipPingMessage(string destinationID, string senderID, string sipServer,
            int sipServerPort, byte[] bytesToSend)
        {
            Message pingMessage = new Message();
            pingMessage.Uri = "sip:" + destinationID + "@" + sipServer + ":" + sipServerPort;
            pingMessage.From = new ContactInfo(string.Format("sip:{0}@{1}", senderID, sipServer));
            pingMessage.To = new ContactInfo(string.Format("sip:{0}@{1}", destinationID, sipServer));
            //message.Contact = new Contact("sip:" + tbUsername.Text + "@" + _sipClient.LocalIPEndPoint.ToString());

            // byte 0 - 1   length (2 - bytes) = nr of bytes following
            // byte 2       Type (1 - byte) = 0x02 = SUP Type - UI
            // byte 3       Command = 0xA0
            // byte 4 - 7   Radio ID (Target or source)
            // byte 8 - end Management payload = as described in 3.2 -  Management Payload

            byte[] ping = Simoco.SP6.PingCommand(bytesToSend);
            pingMessage.ContentType = "application/octet-stream";
            pingMessage.Body = Convert.ToBase64String(ping);
            pingMessage.Header.Add("Ais-Reach", "individual");
            // Softul de pe AIS are nevoie de punct si virgula (;) dupa short-data
            pingMessage.Header.Add("Ais-Service", "short-data;");
            pingMessage.Header.Add("Ais-Options", "service-attributes; coding=iso8");
            pingMessage.Header.Add("Content-Transfer-Encoding", "base64");

            return pingMessage;
        }

        private Message GenerateExceraRadioCheckMessage(string destinationID, string senderID, string sipServer,
            int sipServerPort)
        {
            Message pingMessage = new Message();
            pingMessage.Uri = "sip:" + destinationID + "@" + sipServer + ":" + sipServerPort;
            pingMessage.From = new ContactInfo(string.Format("sip:{0}@{1}", senderID, sipServer));
            pingMessage.To = new ContactInfo(string.Format("sip:{0}@{1}", destinationID, sipServer));

            pingMessage.Header.Add("Ais-Msg-id", "radio-check-rq");
            pingMessage.Header.Add("Ais-Service", "ms-supp");
            
            return pingMessage;
        }

        private Message GenerateSimocoAckForDeviceStatusReport(string destinationID, string senderID, string sipServer,
            int sipServerPort, string text)
        {
            Message ackMessage = new Message();
            ackMessage.Uri = "sip:" + destinationID + "@" + sipServer + ":" + sipServerPort;
            ackMessage.From = new ContactInfo(string.Format("sip:{0}@{1}", senderID, sipServer));
            ackMessage.To = new ContactInfo(string.Format("sip:{0}@{1}", destinationID, sipServer));
            //message.Contact = new Contact("sip:" + tbUsername.Text + "@" + _sipClient.LocalIPEndPoint.ToString());

            ackMessage.ContentType = "application/octet-stream";
            ackMessage.Body = text;

            // Softul de pe AIS are nevoie de punct si virgula (;) dupa short-data
            ackMessage.Header.Add("Ais-Service", "short-data;");
            ackMessage.Header.Add("Ais-Options", "service-attributes; coding=iso8");

            return ackMessage;
        }

        private Message GenerateSipGpsRequestMessage(string destinationID, string senderID, string sipServer,
            int sipServerPort)
        {
            Message gpsReqMessage = new Message();
            gpsReqMessage.Uri = "sip:" + destinationID + "@" + sipServer + ":" + sipServerPort;
            gpsReqMessage.From = new ContactInfo(string.Format("sip:{0}@{1}", senderID, sipServer));
            gpsReqMessage.To = new ContactInfo(string.Format("sip:{0}@{1}", destinationID, sipServer));
            gpsReqMessage.ContentType = "application/octet-stream";
            gpsReqMessage.ContentEncoding = "base64";

            byte[] gpsRequest = Simoco.SP6.GPSRequestCommand();
            gpsReqMessage.Body = Convert.ToBase64String(gpsRequest);
            
            // Softul de pe AIS are nevoie de punct si virgula (;) dupa short-data
            gpsReqMessage.Header.Add("Ais-Service", "short-data;");
            gpsReqMessage.Header.Add("Ais-Options", "service-attributes; coding=iso8");
            gpsReqMessage.Header.Add("Content-Transfer-Encoding", "base64");

            return gpsReqMessage;
        }

        private bool SmsConfirmedBySipServer(object unconfirmedSmsKey)
        {
            bool smsConfirmed = true;
            bool timeoutNotExpired = true;
            string smsKey = (string)unconfirmedSmsKey;
            lock (_lockerSmsSet)
            {
                while (_smsSentDict.ContainsKey(smsKey) && !_smsSentDict[smsKey].HasValue)
                {
                    smsConfirmed = false;
                    timeoutNotExpired = System.Threading.Monitor.Wait(_lockerSmsSet, SecondsToWaitForSmsConfirmation * 1000);
                    if (!timeoutNotExpired)
                    {
                        // timer expired, no confiramtion received
                        // delete the message from set
                        _smsSentDict.Remove(smsKey);
                        break;
                    }
                }
            }
            if (timeoutNotExpired) // check confirmation status
            {
                lock (_lockerSmsSet)
                {
                    if (_smsSentDict.ContainsKey(smsKey) && _smsSentDict[smsKey].HasValue)
                    {
                        // Check confirmation status
                        smsConfirmed = _smsSentDict[smsKey].Value;
                        // Remove from dictionary
                        _smsSentDict.Remove(smsKey);
                    }
                    else
                        throw new ApplicationException("Error on working with unconfirmed sms dict");
                }
            }
            return smsConfirmed;
        }

        /// <summary>
        /// Mehod used to check if you are in dialog with a sip id
        /// </summary>
        /// <param name="sipID">The sip id</param>
        /// <returns>True if you are in dialog, else returns false</returns>
        public bool InDialogWith(string sipID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            lock (_lockerSipDialog)
            {
                return _IDdialogTuple.ContainsKey(sipID);
            }
        }

        /// <summary>
        /// Stops registration by sending unregister request to the sip server
        /// <para>Releases all the used resources</para>
        /// <param name="async">If true, method returns before all the resources are released</param>
        /// </summary>
        public virtual void Stop(bool async = true)
        {
            if (!_sipClassClosed)
            {
                _sipClassClosed = true;
                List<string> sipIDs = new List<string>();
                Task task = null;
                Task t = Task.Factory.StartNew(() =>
                {
                    // 1.  Reject all calls not answered yet
                    sipIDs.Clear();
                    lock (_lockerCallingMe)
                    {
                        foreach (string callingID in _IDreceivedInviteDict.Keys)
                            sipIDs.Add(callingID);
                    }
                    foreach (string sipID in sipIDs)
                    {
                        Decline_private(sipID, out task);
                        if (task != null)
                            task.Wait();
                    }

                    // 2. Cancel all sent calls
                    sipIDs.Clear();
                    lock (_lockerSipDialog)
                    {
                        foreach (string calledSipID in _IDsentInviteDict.Keys)
                            sipIDs.Add(calledSipID);
                    }
                    foreach (string sipID in sipIDs)
                    {
                        CancelInvite_private(sipID, out task);
                        if (task != null)
                            task.Wait();
                    }

                    // 3. Close all curent dialogs
                    sipIDs.Clear();
                    lock (_lockerSipDialog)
                    {
                        foreach (string idInDialog in _IDdialogTuple.Keys)
                            sipIDs.Add(idInDialog);
                    }
                    foreach (string sipID in sipIDs)
                    {
                        Close_private(sipID, out task, DialogClosedReason.NormalClosing);
                        if (task != null)
                            task.Wait();
                    }

                    // Stop registering to sip server
                    StopRegisterToSipServer();
                    // Unregister events
                    _sipClient.ReceiveRequest -= ProcessSipRequest;
                    _sipClient.ReceiveResponse -= ProcessSipResponse;
                    // Stop sip class
                    _sipClient.Disconnect();
                });
                if (!async)
                    t.Wait();
            }
        }

        /// <summary>
        /// Stops registration by sending unregister request to the sip server
        /// </summary>
        public void StopRegisterToSipServer()
        {
            // Stop registering to groups
            List<string> idsToUnregisterFrom = new List<string>(_IDsregisteredList);
            RegistrationData zeroRegistrationData = null;
            foreach (string id in idsToUnregisterFrom)
            {
                if (id != _sipClient.Username)
                    zeroRegistrationData = new RegistrationData(id, 0, true);
                else
                    zeroRegistrationData = new RegistrationData(id, 0);
                _sipID_regTimer_regStatus_Dict[id].Item1.Stop();
                SendSipRegister(zeroRegistrationData);
            }
            //foreach (string groupID in _groupID_regTimer_regStatus_Dict.Keys)
            //{
            //    RegistrationData zeroRegistrationGroup = new RegistrationData(groupID, 0, true);
            //    _groupID_regTimer_regStatus_Dict[groupID].Item1.Stop();
            //    SendSipRegister(zeroRegistrationGroup);
            //}

            /*
            // Stop registering to the sip id
            if (_registrationTimer.Enabled)
            {
                _registrationTimer.Stop();
                RegistrationData zeroRegistration = new RegistrationData(_sipClient.Username, 0);
                SendSipRegister(zeroRegistration);
            }
             */ 
            
        }

        /// <summary>
        /// Register the Sip class to a simoco group id
        /// </summary>
        /// <param name="simocoGroupID">id of the simoco group</param>
        protected void RegisterToSimocoGroup(string simocoGroupID)
        {
            if (_sipClassClosed)
                throw new ObjectDisposedException("SipClientClass");
            if (simocoGroupID != null)
            {
                if (_forSimoco)
                {
                    if (!_sipID_regTimer_regStatus_Dict.ContainsKey(simocoGroupID))
                    {
                         // Create a timer for sending registration to simoco group
                        // Simoco accepts only an expire value of max 30s
                        int registrationInterval = _rand.Next(17, 31);
                        System.Timers.Timer timer = new System.Timers.Timer(registrationInterval * 1000);
                        timer.Elapsed += (sender, e) =>
                        {
                            SendSipRegister(new RegistrationData(simocoGroupID, registrationInterval + 2, true));
                        };
                        // Start the timer
                        timer.Start();
                        _sipID_regTimer_regStatus_Dict.Add(simocoGroupID, new Tuple<System.Timers.Timer, RegistrationStatus>(timer, RegistrationStatus.RegistrationNotStarted
));
                        _IDsregisteredList.Add(simocoGroupID);
                        // Send register to group
                        Task.Factory.StartNew(() => 
                        {
                            SendSipRegister(new RegistrationData(simocoGroupID, registrationInterval + 2, true));
                        });
                    }
                }
                else
                    throw new SipClassException("Cannot register to Simoco group if simoco parameter was not set in constructor!");
            }
            else
                throw new ArgumentNullException("simocoGroupID");
        }

        #endregion


        #region RTP Listener Event Handlers

        private void ReceivedVoice(object sender, AudioEventArgs e)
        {
            OnVoiceReceived(e);
        }

        void PTTControlReceived(object sender, PTTEventArgs e)
        {
            string sipIDSendingRTP = e.RadioID.ToString();
            string sipIDinDialogWith = e.SipIDinDialogWith.ToString();
            if (!_IDdialogTuple.ContainsKey(sipIDinDialogWith))
                return;
            RTPSender2 rtpSender = _IDdialogTuple[sipIDinDialogWith].Item2;
            RTPListener2 rtpListener = _IDdialogTuple[sipIDinDialogWith].Item3;
            TimerWithTag<string> timerHangtime = _IDdialogTuple[sipIDinDialogWith].Item4;
            switch (e.PTTTypeEnum)
            {
                case PTT_Type.Request:
                    PTTrequestEventArgs ev = new PTTrequestEventArgs(sipIDSendingRTP);
                    OnPTTrequestReceived(ev);
                    if (ev.Grant.HasValue)
                    {
                        if (ev.Grant.Value)
                        {
                            rtpListener.SetRequestedTSNstatus(new TSNinfo(e.TSN) { Status = TSNstatus.Granted });
                            rtpSender.SendPTTGrant(e.TSN);
                        }
                        else
                        {
                            rtpListener.SetRequestedTSNstatus(new TSNinfo(e.TSN) { Status = TSNstatus.Denied });
                            rtpSender.SendPTTDeny(e.TSN);
                        }
                    }
                    break;
                case PTT_Type.Grant:
                    // Received grant for ptt
                    // Verific tsn-ul
                    if (rtpSender.IsRequestingPTT(e.TSN))
                    {
                        // Stop sending PTT requests
                        rtpSender.StopSendingPTTrequests(true);
                        OnPTTrequestGranted(sipIDSendingRTP, rtpListener.IsGroupCall);
                    }
                    break;
                case PTT_Type.Progress:
                    break;
                case PTT_Type.End:
                    // Start the hangtime timer
                    if (timerHangtime != null)
                    {
                        timerHangtime.Start();
                    }
                    OnPTTEndReceived(new RtpEventArgs(sipIDinDialogWith, sipIDSendingRTP));
                    break;
                case PTT_Type.Start:
                    // Stop the hangtime timer
                    if (timerHangtime != null)
                    {
                        timerHangtime.Stop();
                    }
                    OnPTTStartReceived(new RtpEventArgs(sipIDinDialogWith, sipIDSendingRTP));
                    break;
                case PTT_Type.Deny:
                    // Received Deny for ptt
                    // Verific tsn-ul
                    if (rtpSender.IsRequestingPTT(e.TSN))
                    {
                        // Stop sending PTT requests
                        rtpSender.StopSendingPTTrequests(false);
                        // Send PTT End
                        rtpSender.SendPTTEnd();
                        // Fire Event
                        OnPTTrequestDenied(sipIDSendingRTP);
                    }
                    break;
                case PTT_Type.Heartbeat:
                    // Stop sending PTT heartbeat query
                    rtpSender.StopSendingHeartbeatQuery();
                    // Start sending PTT heartbeat
                    rtpSender.StartSendingHeartbeat();
                    break;
                case PTT_Type.HeartbeatQuery:
                    // Respond whith Heartbeat
                    // Start heatbeat queary
                    rtpSender.StartSendingHeartbeat();
                    break;
                default:
                    break;
            }
        }

        void TimerAliveExpired(object sender, EventArgs e)
        {
            // Close the Sip Session with Bye
            RTPListener2 rtpListener = (RTPListener2)sender;
            //Close(rtpListener.SipIDinDialogWith.ToString());
            Task t = null;
            Close_private(rtpListener.SipIDinDialogWith.ToString(), out t, DialogClosedReason.TimerAliveTimeExpired);
        }


        void ExceptionThrown(object sender, EventArgs e)
        {
            RTPListener2 rtpListener = (RTPListener2)sender;
            // Close the Sip Session with Bye
            /*
            Task t = null;
            Close_private(rtpListener.SipIDinDialogWith.ToString(), out t, DialogClosedReason.Error);
            */

            // A better (?) solution would be to start the listener again
            rtpListener.Start();
        }

        #endregion

        #region RTP Sender Event Handlers

        void MaximumNbOfPttRequestsWasSent(object sender, EventArgs e)
        {
            RTPSender2 rtpSender = (RTPSender2)sender;
            OnPTTrequestFailed(rtpSender.DMR_Destination.ToString());
        }

        void rtpSender_SendingPTTStart(object sender, EventArgs e)
        {
            // Stop the hangtime timer
            RTPSender2 rtpSender = (RTPSender2)sender;
            string key = rtpSender.DMR_Destination.ToString();
            if (_IDdialogTuple.ContainsKey(key))
            {
                TimerWithTag<string> timer = _IDdialogTuple[key].Item4;
                if (timer != null)
                {
                    timer.Stop();
                }
            }
        }

        #endregion

        #region Abstract

        internal abstract SipMessageGenerator SipMessageGenerator { get; }

        internal abstract RTPListener2 CreateRTPListener(UdpClient udpClient, bool initiatedByMe, int bufferMiliseconds, int sipIdInDialogWith, bool isGroupCall, TypeOfCall typeOfCall);

        internal abstract RTPSender2 CreateRTPSender(UdpClient udpClient, int audioBitrate, IPEndPoint iPEndPoint, int dmrSourceID, int dmrDestinationID, bool initiatedByMe, TypeOfCall typeOfCall, 
            RtpCallType halfDuplexCallType = RtpCallType.Private);

        #endregion


        #region Private Sip Functions

        private void ProcessSipResponse(object sender, ResponseEventArgs e)
        {
            Response resp = e.Response;
            string responserRadioID = resp.To.Address.Split(':', '@')[1];
            switch (resp.StatusCode)
            {
                case 200: // OK response
                    if (resp.CSeq.Contains("INVITE")) // OK response for an Invite
                    {
                        bool success = false;
                        string errorMsg = "";
                        bool isGroupCall = false;
                        TypeOfCall typeOfCall = TypeOfCall.HALF_DUPLEX;
                        // Gasesc Invite-ul pentru care am primit OK
                        lock (_lockerSipDialog)
                        {
                            if (_IDsentInviteDict.ContainsKey(responserRadioID))
                            {
                                Invite sentInvite = _IDsentInviteDict[responserRadioID];
                                // Check if it was group invite
                                if (sentInvite.Header.ContainsKey("Ais-Reach"))
                                    if (sentInvite.Header["Ais-Reach"] == "group")
                                        isGroupCall = true;
                                // Get the type: full or half duplex
                                typeOfCall = GetTypeOfCall(resp.SessionDescription);
                                try
                                {
                                    // Send sip Ack
                                    _sipClient.Ack(resp);
                                    // Creez Dialogul
                                    CreatingDialog(responserRadioID,
                                        isGroupCall,
                                        resp.SessionDescription,
                                        typeOfCall,
                                        sentInvite.SessionDescription.Media[0].Port,
                                        true);
                                    success = true;
                                }
                                catch (Exception ex)
                                {
                                    // Nu am reusit sa setez dialogul
                                    errorMsg = ex.Message;
                                    // Fac DialogClosed();
                                    bool wasGroupCall;
                                    if (ClosingDialog(responserRadioID, _sipClient.Username, out wasGroupCall))
                                    {
                                        // Trimit Bye
                                        Task.Factory.StartNew((respObj) =>
                                        {
                                            _sipClient.Bye((Response)respObj);
                                        }, resp);
                                    }
                                }
                                finally
                                {
                                    // Remove from sent invites dictionary
                                    _IDsentInviteDict.Remove(responserRadioID);
                                    _IDsCalledByMeList.Remove(responserRadioID);
                                }
                            }
                            else // OK primit pentru un Invite anulat...
                            {
                                errorMsg = "Received OK for a cancelled Invite";
                                // Trimit Bye sau Cancel???
                                // Din standard se pare ca Bye
                                //Task.Factory.StartNew((respObj) =>
                                //{
                                //    _sipClient.Bye((Response)respObj);
                                //}, resp);

                                // TO DO - to verify this
                                // That weird situation with Asterisk sending multiple requests / response
                                // Don't do anything, just return
                                break;
                            }
                        }
                        if (success)
                            OnDialogCreated(new DialogCreatedEventArgs(responserRadioID, _sipClient.Username, typeOfCall, isGroupCall));
                        else
                            OnError(new ErrorEventArgs(responserRadioID, _sipClient.Username, errorMsg));
                    }
                    break;
                case 100: // Trying
                    break;
                case 180: // Ringing
                    break;
                case 401: // Unauthorized (temporarely)
                    break;
                case 202: // Accepted
                    break;
                default: // Probabil eroare
                    // trimit Ack
                    // I don't send ack because the sip.NET library does not send it to the correct udp port
                    // This happens only with Asterisk, for Linx project
                    // It use to work for simoco
                    //_sipClient.Ack(resp);
                    bool fireEvent = false;
                    lock (_lockerSipDialog)
                    {
                        if (_IDsentInviteDict.ContainsKey(responserRadioID))
                        {
                            _IDsentInviteDict.Remove(responserRadioID);
                            _IDsCalledByMeList.Remove(responserRadioID);
                            fireEvent = true;
                        }
                    }
                    if (fireEvent)
                        OnError(new ErrorEventArgs(responserRadioID, _sipClient.Username, resp.Description));
                    break;
            }
        }

        private void ProcessSipRequest(object sender, RequestEventArgs e)
        {
            Request req = e.Request;
            string requesterRadioId = req.From.Address.Split(':', '@')[1];
            string requesterTargetId = req.To.Address.Split(':', '@')[1];
            switch (req.Method)
            {
                case SipMethod.Invite:
                    bool fireEvent = false;
                    string idInDialogWith = requesterRadioId;
                    bool isEmergencyCall = false;
                    TypeOfCall typeOfCall = TypeOfCall.FULL_DUPLEX;
                    // Send quickly a trying before analysing the request (Excera suggestion)
                    _sipClient.SendResponseTrying(req);
                    lock (_lockerCallingMe)
                    {
                        if (!_IDreceivedInviteDict.ContainsKey(requesterRadioId))
                        {
 
                            // Check if is group invite (Simoco)
                            if (req.Header.Contains("Ais-Reach"))
                            {
                                if (req.Header["Ais-Reach"] == "group")
                                {
                                    if (_forSimoco)
                                    {
                                        idInDialogWith = requesterTargetId;
                                    }
                                    else
                                    {
                                        _sipClient.SendResponseBusyHere(req);
                                        break;
                                    }
                                }
                            }

                            // Check if is emergency call (Simoco)
                            if (req.Header.Contains(StandardHeader.Priority))
                                if (req.Header[StandardHeader.Priority] == "emergency")
                                    isEmergencyCall = true;

                            // Check if is full or half duplex
                            try
                            {
                               typeOfCall = GetTypeOfCall(req);
                            }
                            catch (ArgumentException)
                            {
                                // Invite was not correctly formated
                                // send busyHere
#if DEBUG
                                Console.WriteLine("Received the following incorrect invite:" + System.Environment.NewLine + req.ToString());
#endif
                                _sipClient.SendResponseBusyHere(req);
                                break;
                            }
                            catch (Exception)
                            {
                                // TO DO - for now do nothing to see the error
                                //_sipClient.SendResponseBusyHere(req);
                                //break;
                            }

                            if (SendResponseRinging(req, requesterRadioId))
                            {
                                // Sent response Ringing
                                _sipClient.SendResponseRinging(req);
                                // Add to dictionary
                                _IDreceivedInviteDict.Add(idInDialogWith, req);
                                _IDsCallingMeList.Add(idInDialogWith);
                                // fire event
                                fireEvent = true;
                            }
                            else
                            {
                                _sipClient.SendResponseBusyHere(req);
                            }
                        }
                    }
                    if (fireEvent)
                    {
                       OnInviteReceived(new InviteReceivedArgs(idInDialogWith, requesterRadioId, typeOfCall, isEmergencyCall));
                    }
                    break;
                case SipMethod.Bye:
                    // Accept the request
                    _sipClient.AcceptRequest(req);

                    string idToClose = requesterRadioId;
                    if (requesterTargetId != _sipClient.Username)
                        idToClose = requesterTargetId; // This is for Simoco group calls, when a radio sends Bye
                    bool wasGroupCall;
                    if (ClosingDialog(idToClose, requesterRadioId, out wasGroupCall))
                    {
                        // FireEvent;
                        OnDialogClosed(new DialogClosedEventArgs(
                            idToClose, requesterRadioId, wasGroupCall, DialogClosedReason.NormalClosing));
                    }
                    break;
                case SipMethod.Cancel:
                    // Accept the request
                    _sipClient.AcceptRequest(req);
                    fireEvent = false;
                    // Check if Bye request is for an open dialog

                    lock (_lockerCallingMe)
                    {
                        if (_IDreceivedInviteDict.ContainsKey(requesterRadioId))
                        {
                            // remove from dictionary
                            _IDreceivedInviteDict.Remove(requesterRadioId);
                            _IDsCallingMeList.Remove(requesterRadioId);
                            // Fire event 
                            fireEvent = true;
                        }
                    }
                    if (fireEvent)
                        OnInviteReceivedCanceled(new SipEventArgs(requesterRadioId));
                    break;
                case SipMethod.Ack:
                    // Since Excera, I don't require the ACK message to have a Contact header
                    //if (req.Header.Contains(StandardHeader.Contact)) 
                    //{
                        // We received an Invite, sent Ok and now we receive ack
                        bool isGroupCall = false;
                        GetInfoFromAckRequest(requesterRadioId, requesterTargetId, out idInDialogWith, out isGroupCall);

                        // Dialog confirmed ?
                        if (_IDdialogTuple.ContainsKey(idInDialogWith))
                        {
                            
                            
                            OnDialogCreated(new DialogCreatedEventArgs(
                                requesterTargetId, 
                                requesterRadioId,
                                _IDdialogTuple[idInDialogWith].Item2.TypeOfCall,
                                isGroupCall));
                        }
                    //}
                    break;
                case SipMethod.Message:
                    // Accept the request
                    _sipClient.AcceptRequest(req);
                    ProcessReceivedSipMessage(req, requesterRadioId);
                    break;
                case SipMethod.Info:
                case SipMethod.Notify:
                case SipMethod.Options:
                case SipMethod.Prack:
                case SipMethod.Publish:
                case SipMethod.Refer:
                case SipMethod.Register:
                case SipMethod.Subscribe:
                case SipMethod.Update:
                default:
                    // Accept request
                    _sipClient.AcceptRequest(req);
                    break;
            }
        }

        /// <summary>
        /// Method used to decide if the app is ringing or is sending Busy response to sender
        /// <para>Default behaviour is to ring (sends Ringing response)</para>
        /// </summary>
        /// <param name="receivedInvite">The received invite</param>
        /// <param name="senderSipId">The sender of the invite</param>
        /// <returns>True to send Ringing response, false to send Busy Here</returns>
        protected virtual bool SendResponseRinging(Request receivedInvite, string senderSipId)
        {
            return true;
        }

        /// <summary>
        /// Function that processes all the received Sip Message requests
        /// </summary>
        /// <param name="sipMessageRequest">The Sip Message request</param>
        /// <param name="senderID">The ID of the sender</param>
        protected virtual void ProcessReceivedSipMessage(Request sipMessageRequest, string senderID)
        {
            
            // Handle messages when working with Simoco (Or gps messages sent exactly as Simoco does)
            // Get Ais-Options Header value
            if (sipMessageRequest.Header.Contains("Ais-Options"))
            {
                string ais_options = sipMessageRequest.Header["Ais-Options"];
                switch (ais_options)
                {
                    case "service-attributes; coding=nmea":
                        // GPS periodically report
                        double lat, lon, speed;
                        DateTime time;
                        // Get latitude, longitude, speed and time
                        Simoco.Utils.GPSInfo(Convert.FromBase64String(sipMessageRequest.Body), out lat, out lon, out speed, out time);
                        // Raise Event
                        OnGpsPeriodicallyReportReceived(new GpsDataEventArgs(
                            senderID, lat, lon, speed, time));
                        break;
                    case "service-attributes; coding=iso8":
                        // Management message report
                        // Get the Type and the command bytes
                        byte[] data = Convert.FromBase64String(sipMessageRequest.Body);
                        byte type = SipComponent.Simoco.SP6.GetType(data);
                        byte command = SipComponent.Simoco.SP6.GetCommand(data);
                        switch (type)
                        {
                            case 0:
                                // GPS position report
                                byte[] nmeaData = new byte[10];
                                Array.Copy(data, 5, nmeaData, 0, nmeaData.Length);
                                // Get latitude, longitude, speed and time from nmea data
                                Simoco.Utils.GPSInfo(nmeaData, out lat, out lon, out speed, out time);
                                // Raise event
                                OnSimocoGpsReportReceived(new GpsDataEventArgs(senderID, lat, lon, speed, time));
                                break;
                            case 1:
                                // Device status
                                switch (command)
                                {
                                    case 1:
                                        // Device status report
                                        // Sent on request or when alarm conditions change
                                        // Is sent to remote radio to acknowledge receipt of alarm conditions

                                        // Get GPS from status report
                                        Simoco.Utils.GetGPSFromStatusReport(data, out lat, out lon);
                                        Simoco.AlarmType alarmType = Simoco.SP6.GetAlarmType(data);
                                        if (alarmType != Simoco.AlarmType.NO_ALARM)
                                        {
                                            // Save the message in a dictionary
                                            // It have to be resent to the radio to confirm the receipt
                                            AddSimocoAlarmToDictionary(senderID, sipMessageRequest.Body);
                                        }
                                        // Raise event
                                        OnSimocoStatusReportReceived(new SimocoDeviceStatusReportEventArgs(
                                            senderID, lat, lon, alarmType));
                                        break;
                                }
                                break;
                            case 255:
                                // Ping
                                int nbOfReceivedBytes = data.Length - 5;
                                byte[] pingData = new byte[nbOfReceivedBytes];
                                Array.Copy(data, 5, pingData, 0, pingData.Length);
                                if (HandleSimocoPingResponse(senderID, pingData))
                                {
                                    // Fire Event
                                    OnSimocoPingResponseReceived(new SipEventArgs(senderID));
                                }
                                break;
                        }
                        break;
                    default:
                        // This is surelly incorect - TO DO
                        // Sms from Simoco
                        if (_forSimoco)
                        {
                            string text = sipMessageRequest.Body;
                            if (text != null) // body is null in case of status message - future implementation - TO DO
                            {
                                OnSmsReceived(new SmsReceivedEventsArgs(senderID,
                                    Encoding.BigEndianUnicode.GetString(Convert.FromBase64String(text))
                                    ));
                            }
                        }
                        break;
                }
            } 
            else if (!_forSimoco)
            {
                // Handle messages when working with Asterisk server (set up by Andrei)
                if (sipMessageRequest.ContentType == "text/plain;charset=UTF-8")
                {
                    // SMS received 
                    if (senderID == "Unknown")
                    {
                        // SMS confirmation from Sip server
                        if (_smsConfirmationFromServer)
                        {
                            // Get sms destination and message
                            string smsKey = GetSmsKeyFromConfirmation(sipMessageRequest.Body);
                            lock (_lockerSmsSet)
                            {
                                if (_smsSentDict.ContainsKey(smsKey))
                                {
                                    // Set message as delivered or failed
                                    _smsSentDict[smsKey] = GetDeliveredStatusFromConfirmation(sipMessageRequest.Body);
                                    // Notify that we received a confirmation
                                    Monitor.PulseAll(_lockerSmsSet);
                                }
                            }
                        }
                    }
                    else if (sipMessageRequest.Header.Contains("Ais-Service"))
                    {
                        if (sipMessageRequest.Header["Ais-Service"] == "mbus")
                        {
                            string messageBody = sipMessageRequest.Body;
                            if (messageBody != null)
                            {
                                string[] tmp = messageBody.Split('#');
                                if (tmp.Length >= 4 && messageBody.Length == Convert.ToInt32(tmp[1]))
                                {
                                    switch (tmp[3])
                                    {
                                        case "138":
                                            // Emergency from Linx
                                            if (_previousEmergencySeqID != tmp[2]) // Protection against multiple message error
                                            {
                                                _previousEmergencySeqID = tmp[2];
                                                Linx.LinxEmergencyType type = Linx.LinxEmergencyType.REGULAR;
                                                if (tmp[5] != null)
                                                {
                                                    int emergencyType;
                                                    if (int.TryParse(tmp[5], out emergencyType))
                                                    {
                                                        if (Enum.IsDefined(typeof(Linx.LinxEmergencyType), emergencyType))
                                                        {
                                                            type = (Linx.LinxEmergencyType)emergencyType;
                                                        }
                                                    }
                                                }
                                                OnLinxEmergencyAlarmReceived(new Linx.LinxEmergencyAlarmReceivedEventArgs(senderID, tmp[2], type));
                                            }
                                            break;
                                        case "131": // Periadically gps from Linx
                                        case "231": // Polled gps from Linx
                                            int unixTime;
                                            double speed, latitude, longitude;
                                            if (tmp.Length >= 9)
                                            {
                                                // Protection against multiple message error
                                                if (_previousLocationSeqID != tmp[2])
                                                    _previousLocationSeqID = tmp[2];
                                                else
                                                    break;
                                                if (double.TryParse(tmp[6], NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out speed))
                                                {
                                                    if (int.TryParse(tmp[5], out unixTime))
                                                    {
                                                        if (double.TryParse(tmp[7], NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingWhite | NumberStyles.AllowLeadingSign, CultureInfo.InvariantCulture, out latitude))
                                                        {
                                                            if (double.TryParse(tmp[8], NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingWhite | NumberStyles.AllowLeadingSign, CultureInfo.InvariantCulture, out longitude))
                                                            {
                                                                if (tmp[3] == "131")
                                                                {
                                                                    // Periodically gps from Linx
                                                                    OnGpsPeriodicallyReportReceived(new GpsDataEventArgs(
                                                                        senderID, latitude, longitude, speed, UnixTimeStampToDateTime(unixTime)));
                                                                }
                                                                else if (tmp[3] == "231")
                                                                {
                                                                    OnLinxGpsReportReceived(new LinxGpsDataEventArgs(
                                                                        senderID, tmp[2], latitude, longitude, speed, UnixTimeStampToDateTime(unixTime)));
                                                                }
                                                            }
                                                        }
                                                    }
                                                }
                                            }
                                            break;
                                        case "130": // Ars from Linx
                                            if (tmp.Length >= 6)
                                            {
                                                if (_previousArsSeqID != tmp[2])  // Protection against multiple message error
                                                {
                                                    _previousArsSeqID = tmp[2];
                                                    OnLinxArsReceived(new Linx.ArsReceivedEventArgs(senderID, tmp[2], tmp[5] == "ON" ? true : false));
                                                }

                                            }
                                            break;
                                    }

                                }
                            }
                        }
                    }
                    else
                    {
                        // Must be sms (:::seqID:::text:::)
                        string messageBody = sipMessageRequest.Body;
                        if (messageBody != null)
                        {
                            string[] tmp = messageBody.Split(new string[]{ ":::"}, StringSplitOptions.None);
                            if (tmp.Length == 4)
                            {
                                if (_previousSmsSeqID != tmp[1])
                                {
                                    _previousSmsSeqID = tmp[1];
                                    OnSmsReceived(new SmsReceivedEventsArgs(senderID, tmp[2]));
                                }
                            }
                        }
                    }
                }
            }
            
        }

        #region Sms confirmation private helper functions

        private string GetSmsKeyFromConfirmation(string messageBody)
        {
            string toReturn = "";
            int destinationSipID;
            string text;
            if (int.TryParse(GetDestinationIDFromConfirmation(messageBody), out destinationSipID))
            {
                text = GetTextFromConfirmation(messageBody);
                toReturn = destinationSipID.ToString() + text.GetHashCode();
            }
            return toReturn;
        }

        private string GetTextFromConfirmation(string source)
        {
            string start = "Your message - ";
            string end = " - to ";
            int startIndex, endIndex;
            string strToReturn = "";
            if (source.Contains(start) && source.Contains(end))
            {
                startIndex = source.IndexOf(start) + start.Length;
                endIndex = source.LastIndexOf(end);
                strToReturn = source.Substring(startIndex, endIndex - startIndex);
            }
            return strToReturn;
        }

        private string GetDestinationIDFromConfirmation(string source)
        {
            string start = " - to ";
            string end = " has ";
            int startIndex, endIndex;
            string strToReturn = "";
            if (source.Contains(start) && source.Contains(end))
            {
                startIndex = source.LastIndexOf(start) + start.Length;
                endIndex = source.LastIndexOf(end);
                strToReturn = source.Substring(startIndex, endIndex - startIndex);
            }
            return strToReturn;
        }

        private bool GetDeliveredStatusFromConfirmation(string source)
        {
            string lastWord = source.Substring(source.LastIndexOf(' ') + 1);
            if (lastWord.Contains("delivered"))
                return true;
            else if (lastWord.Contains("failed"))
                return false;
            else
                throw new ApplicationException("Error on parsing the sms confirmation from sip server");
        }

        #endregion

        private void CreatingDialog(string sipIdInDialogWith, bool isGroupCall, SessionDescription receivedSDP, TypeOfCall typeOfCall, int localRTPport, bool initiatedByMe)
        {
            lock (_lockerSipDialog)
            {
                if (_IDdialogTuple.Count == MaxNbOfDialogs)
                    throw new ApplicationException("Exceeded the maximum number of simultaneous dialogs: " + MaxNbOfDialogs);
                // Verific daca sunt deja in dialog cu userul
                if (!_IDdialogTuple.ContainsKey(sipIdInDialogWith))
                {
                    // Extract ip and port where to send voice to simoco
                    IPAddress ipToSendAudio = null;
                    int portToSendAudio;
                    if (IPAddress.TryParse(receivedSDP.Connection.Address, out ipToSendAudio))
                    {
                        portToSendAudio = receivedSDP.Media[0].Port;
                    }
                    else throw new ApplicationException("Canot determine ip where to send audio");

                    // Creez clientul de UDP conectat la portul pe care voi primi voce
                    UdpClient udpClient = new UdpClient(localRTPport);
                    //UdpClient udpClient = new UdpClient(new IPEndPoint(IPAddress.Parse(_localIPaddress), localRTPport));

                    // Create RTPSender (trebuie sa fie gata sa trimita mesaje catre simoco) 
                    RTPSender2 rtpSender = CreateRTPSender(
                        udpClient,
                        AudioBitrate,
                        new IPEndPoint(ipToSendAudio, portToSendAudio),
                        int.Parse(_sipClient.Username),
                        int.Parse(sipIdInDialogWith),
                        initiatedByMe,
                        typeOfCall,
                        isGroupCall ? RtpCallType.Group : RtpCallType.Private);
                    rtpSender.SentMaxNumberOfPTTrequests += MaximumNbOfPttRequestsWasSent;
                    rtpSender.SendingPTTStart += rtpSender_SendingPTTStart;

                    //
                    //_pttControlBlockingCollection = new BlockingCollection<PTTEventArgs>();
                    //Task.Factory.StartNew(() => 
                    //{
                    //    ProcessPTTReceived();
                    //});


                    // Incep sa ascult RTP trimis de Simoco
                    RTPListener2 rtpListener = CreateRTPListener(udpClient, initiatedByMe, _bufferMiliseconds, int.Parse(sipIdInDialogWith), isGroupCall, typeOfCall);
                    //_rtpListener.PTTControlReceived += PTTControlReceived;
                    rtpListener.VoiceReceived += ReceivedVoice;
                    rtpListener.PTTControlReceived += PTTControlReceived;
                    rtpListener.TimerAliveExpired += TimerAliveExpired;
                    rtpListener.ExceptionThrown += ExceptionThrown;
                    rtpListener.Start();

                    // Timer hangtime
                    TimerWithTag<string> timerHangTime = null;
                    if (HangTimeDuration != -1)
                    {
                        timerHangTime = new TimerWithTag<string>(HangTimeDuration * 1000, sipIdInDialogWith);
                        timerHangTime.AutoReset = false;
                        timerHangTime.Elapsed += timerHangTime_Elapsed;
                        timerHangTime.Start();
                    }

                    // here I store in the dictionary all the info about this dialog
                    Tuple<UdpClient, RTPSender2, RTPListener2, TimerWithTag<string>> sipDialogTuple = Tuple.Create(udpClient, rtpSender, rtpListener, timerHangTime);

                    // Sunt in dialog cu statia
                    // Add to dictionary
                    _IDdialogTuple.Add(sipIdInDialogWith, sipDialogTuple);
                    _IDsInDialogWithList.Add(sipIdInDialogWith);
                }
                else
                    throw new SipClassException(string.Format("Already in dialog with {0}",
                        sipIdInDialogWith));
            }
        }

       

        void timerHangTime_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            
            // End call
            TimerWithTag<string> timer = (TimerWithTag<string>)sender;
            if (_IDdialogTuple.ContainsKey(timer.Tag))
            {
                Dialog dialogToClose = _sipClient.GetDialogWith(timer.Tag);
                if (dialogToClose != null)
                {
                    string sipIDidDialogWith = timer.Tag;
                    bool wasGroupCall;
                    if (ClosingDialog(sipIDidDialogWith, _sipClient.Username, out wasGroupCall))
                    {
                        // Send Bye
                        Task.Factory.StartNew((dialogToCloseObj) =>
                        {
                            _sipClient.Bye((Dialog)dialogToCloseObj);
                        }, dialogToClose);
                        // Fire event
                        OnDialogClosed(new DialogClosedEventArgs(
                            sipIDidDialogWith, _sipClient.Username, wasGroupCall, DialogClosedReason.TimerHangTimeExpired));
                    }
                }
            }
        }



        private bool ClosingDialog(string idInDialogWith, string idWhoClosedTheDialog, out bool wasGroupCall)
        {
            lock (_lockerSipDialog)
            {
                wasGroupCall = false;
                if (_IDdialogTuple.ContainsKey(idInDialogWith))
                {
                    //lock (_lockerPTTGranted)
                    //{
                    //    if (_canSendVoiceToSimoco)
                    //    {
                    //        OnEndPTTRequest();

                    //        // Inform SD that cannot send voice
                    //        SendInitiateCallResponse(_callType, _seqIDForCallRequest, _rtpSender.DMR_Destination, false);
                    //    }
                    //}

                    Tuple<UdpClient, RTPSender2, RTPListener2, TimerWithTag<string>> dialogTuple = _IDdialogTuple[idInDialogWith];


                    // Opresc timerele (send ptt hearbeat, heartbeat query, etc) din sender
                    dialogTuple.Item2.Stop();
                    // Unregister form the sender events
                    dialogTuple.Item2.SentMaxNumberOfPTTrequests -= MaximumNbOfPttRequestsWasSent;
                    dialogTuple.Item2.SendingPTTStart -= rtpSender_SendingPTTStart;

                    // Get type of call
                    wasGroupCall = dialogTuple.Item3.IsGroupCall;
                    // Opresc citirea pachetelor rtp
                    dialogTuple.Item3.Stop();
                    // Unregister form the lister events
                    dialogTuple.Item3.PTTControlReceived -= PTTControlReceived;
                    dialogTuple.Item3.TimerAliveExpired -= TimerAliveExpired;
                    dialogTuple.Item3.VoiceReceived -= ReceivedVoice;
                    

                    // Close the udp port
                    dialogTuple.Item1.Close();

                    // dispose pentru _rtpListener
                    dialogTuple.Item3.Dispose();

                    // Opresc timerul hangtime
                    if (dialogTuple.Item4 != null)
                    {
                        dialogTuple.Item4.Elapsed -= timerHangTime_Elapsed;
                        dialogTuple.Item4.Stop();
                    }


                    _IDdialogTuple.Remove(idInDialogWith);
                    _IDsInDialogWithList.Remove(idInDialogWith);
                    return true;

                }
                else
                {
                    return false;
                }
            }

        }

        private SipClient CreateSipClientClass(string sipDomain, int sipDomainPort, string localIPaddress, int localSipPort, string userName, string password, int requestTimeout)
        {
            SipClient sipClient;
            // Set up the master SIP class
            sipClient = new SipClient(sipDomain, sipDomainPort, Independentsoft.Sip.ProtocolType.Udp, userName, password);
            sipClient.LocalIPEndPoint = new IPEndPoint(IPAddress.Parse(localIPaddress), localSipPort);
            // Turn on logging
            //sipClient.Logger = new Logger(AppDomain.CurrentDomain.BaseDirectory + "\\sipLog.txt");
            sipClient.ReceiveRequest += ProcessSipRequest;
            sipClient.ReceiveResponse += ProcessSipResponse;
            sipClient.Timeout = requestTimeout;

            sipClient.Connect();
            _sipClassClosed = false;
            return sipClient;
        }

        private void SendSipInvite(string idToCall, TypeOfCall typeOfCall, bool isSimocoGroup = false)
        {
            lock (_lockerSipDialog)
            {
                if (!_IDsentInviteDict.ContainsKey(idToCall))
                {
                    // Send invite to somewone
                    string sipServerIP = _sipClient.Domain;
                    string sipID = _sipClient.Username;

                    int rtpPort = ReturnAvailablePort();
                    SessionDescription sdp = CreateSDP(rtpPort, typeOfCall);
                    Invite inv = new Invite();
                    inv.Uri = "sip:" + idToCall + "@" + sipServerIP;
                    inv.From = new ContactInfo("sip:" + sipID.ToString() + "@" + sipServerIP);
                    inv.To = new ContactInfo("sip:" + idToCall + "@" + sipServerIP);
                    inv.Contact = new Contact("sip:" + sipID.ToString() + "@" + _sipClient.LocalIPEndPoint.ToString());
                    inv.SessionDescription = sdp;
                    inv.Subject = typeOfCall.ToString();

                    if (isSimocoGroup)
                        inv.Header.Add("Ais-Reach", "group");
                    else
                        inv.Header.Add("Ais-Reach", "individual");

                    // Add to dictionary
                    _IDsentInviteDict.Add(idToCall, inv);
                    _IDsCalledByMeList.Add(idToCall);

                    // Send invite request
                    Task.Factory.StartNew((idToCallObj) =>
                    {
                        string id = (string)idToCallObj;
                        OnInviteSent(new SipEventArgs(id));
                        try
                        {
                            _sipClient.SendRequest(inv);
                        }
                        catch (Exception tEx)
                        {
                            // Timout exception

                            // Cancel the invite
                            Task t = null;
                            SendCancelRequest(id, t);
                            // Fire event
                            OnError(new ErrorEventArgs(id, _sipClient.Username, tEx.Message));
                        }

                    }, idToCall);
                }
            }
        }

        private void SendSipRegister(object registrationDataObj)
        {
            string sipServerIP = _sipClient.Domain;
            RegistrationData regData = (RegistrationData)registrationDataObj;
            string sipIDfrom = _sipClient.Username;
            string sipIDto = regData.SipID;
            int expiresValue = regData.Expires;
            bool isUnregisterRequest = (expiresValue == 0);

            Register reg = new Register();
            reg.Uri = "sip:" + sipServerIP;
            reg.From = new ContactInfo(
                sipIDfrom.ToString(),
                "sip:" + sipIDfrom + "@" + sipServerIP);
            reg.To = new ContactInfo(
                sipIDto.ToString(),
                "sip:" + sipIDto.ToString() + "@" + sipServerIP);
            reg.Contact = new Contact("sip:" + sipIDfrom.ToString() + "@" + _sipClient.LocalIPEndPoint.ToString());
            reg.Expires = expiresValue;

            RegistrationStatus regStatus = _sipID_regTimer_regStatus_Dict[sipIDto].Item2;
            if (regData.SimocoGroupRegistration)
            {
                reg.Header.Add("Ais-Reach", "group");
            }

            try
            {
                RequestResponse reqResp = _sipClient.SendRequest(reg);
                if (reqResp.Response.StatusCode == 200) //OK
                {
                    if (isUnregisterRequest)
                    {
                        regStatus = RegistrationStatus.UnregisteredAtRequest;
                    }
                    else
                    {
                        regStatus = RegistrationStatus.Registered;
                    }
                }
                else if (reqResp.Response.StatusCode == 403) // 403 = Forbidden
                {
                    regStatus = RegistrationStatus.WrongCredentials;
                }
                else
                {
                    regStatus = RegistrationStatus.NotRegistered;
                    // to do - delete this
                    Console.WriteLine($"Received response: {reqResp.Response.StatusCode} to sip registration request");
                }
            }
            catch (SocketException socketEx)
            {
                regStatus = RegistrationStatus.SocketError;
            }
            catch (Independentsoft.Sip.TimeoutException)
            {
                regStatus = RegistrationStatus.RequestTimeout;
            }
            catch (Exception ex)
            {
                regStatus = RegistrationStatus.NotRegistered;
                // to do - delete this
                Console.WriteLine("Exception when sending registration to Sip server\n" + ex.ToString());
            }

            if (regStatus != _sipID_regTimer_regStatus_Dict[sipIDto].Item2)
            {
                if (regStatus != RegistrationStatus.UnregisteredAtRequest)
                {
                    // Just change the registration status
                    System.Timers.Timer currentTimer = _sipID_regTimer_regStatus_Dict[sipIDto].Item1;
                    _sipID_regTimer_regStatus_Dict[sipIDto] = new Tuple<System.Timers.Timer, RegistrationStatus>(currentTimer, regStatus);
                }
                else
                {
                    // Unregistered - Remove from dictionary
                    _sipID_regTimer_regStatus_Dict.Remove(sipIDto);
                    _IDsregisteredList.Remove(sipIDto);
                }

                OnRegistrationStateChanged(new RegistrationStateChangedEventArgs(sipIDto, regStatus));
                //OnRegistrationStateChanged(    sipIDto, regStatus);
            }
            //try
            //{
            //    RequestResponse reqResp = _sipClient.SendRequest(reg);
            //    if (reqResp.Response.StatusCode == 200) //OK
            //    {
            //        if (isUnregisterRequest)
            //        {
            //            Registered = false;
            //            OnRegistrationStateChanged(sipIDto, RegistrationStatus.UnregisteredAtRequest);
            //        }
            //        else if (!Registered)
            //        {
            //            Registered = true;
            //            OnRegistrationStateChanged(sipIDto, RegistrationStatus.Registered);
            //        }
            //        //Console.WriteLine("Registered to id {0}", sipServerIP);
            //    }
            //    else if (reqResp.Response.StatusCode == 403) // 403 = Forbidden
            //    {
            //        Registered = false;
            //        OnRegistrationStateChanged(sipIDto, RegistrationStatus.WrongCredentials);
            //    }
            //    else
            //    {
            //        if (Registered)
            //        {
            //            Registered = false;
            //            OnRegistrationStateChanged(sipIDto, RegistrationStatus.NotRegistered);
            //        }
            //        //Console.WriteLine("Registration to id {0} failed", sipServerIP);
            //    }
            //}
            //catch (Exception ex)
            //{
            //    if (Registered)
            //    {
            //        Registered = false;
            //        OnRegistrationStateChanged(sipIDto, RegistrationStatus.RequestTimeout);
            //    }
            //}
        }

        /// <summary>
        /// Method used to return the type of call from a received invite
        /// </summary>
        /// <param name="receivedInvite">The received invite</param>
        /// <returns>The requested type of call</returns>
        protected virtual TypeOfCall GetTypeOfCall(Request receivedInvite)
        {
            if (receivedInvite.SessionDescription != null)
            {
                return GetTypeOfCall(receivedInvite.SessionDescription);
            }
            else
                throw new ArgumentNullException("No session description info specified", "receivedInvite");
        }

        /// <summary>
        /// Method used to return the type of call from a received Session description 
        /// </summary>
        /// <param name="sdp">The received session description</param>
        /// <returns>The requested type of call</returns>
        protected virtual TypeOfCall GetTypeOfCall(SessionDescription sdp)
        {
            if (sdp.Media.Count > 0)
            {
                foreach (Independentsoft.Sip.Sdp.Attribute attribute in sdp.Media[0].Attributes)
                {
                    if (attribute.Name == "floor")
                        return TypeOfCall.HALF_DUPLEX;
                }
                return TypeOfCall.FULL_DUPLEX;
            }
            else
                throw new ArgumentException("No types of media specified", "receivedInvite");
        }

        private SessionDescription CreateSDP(int rtpPort, TypeOfCall typeOfCall)
        {
            SessionDescription sdpSession = new SessionDescription();

            // Origin (Owner) - 0=<userName> <sessionId> <version> <network type> <address type>

            // <sessionId> must be unique
            int sessionID = _rand.Next();
            // <version> - must be increased when a modification is made to the session data.
            Owner owner = new Owner(_sipClient.Username, sessionID, 18299, _sipClient.LocalIPEndPoint.Address.ToString());

            Connection connection = new Connection(_sipClient.LocalIPEndPoint.Address.ToString());
            sdpSession.Owner = owner;
            sdpSession.Name = "_";
            sdpSession.Connection = connection;
            sdpSession.Time.Add(new Time(0, 0));
            // m=<media> <port> <transport> <fmt list>
            //   <port> - 1024 to 65535 for UDP
            //          - must be even for RTP
            Media media1 = new Media("audio", rtpPort, "RTP/AVP");
            media1.MediaFormats.Add("8");
            media1.Attributes.Add("rtpmap", "8 PCMA/8000");
            if (typeOfCall == TypeOfCall.HALF_DUPLEX)
                media1.Attributes.Add("floor");
            sdpSession.Media.Add(media1);

            return sdpSession;
        }

        private void StartRegistrationTimer()
        {
            // Send instant registration request
            Task.Factory.StartNew((state) =>
            {
                SendSipRegister(state);
            }, _registrationData);
            // Start registration timer
            _sipID_regTimer_regStatus_Dict[UserName].Item1.Start();
        }

        private void _registrationTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            SendSipRegister(_registrationData);
        }

        #endregion

        #region Private Helper Methods

        /// <summary>
        /// Retrieves the idInDialogWith and the call type from the received ACK request
        /// </summary>
        /// <param name="ackFromSipID">The sip id specified in the From field</param>
        /// <param name="ackToSipId">The sip id specified in the To field</param>
        /// <param name="idInDialogWith">The id that we are in dialog with</param>
        /// <param name="isGroupCall">True if is a group call, else false</param>
        protected void GetInfoFromAckRequest(string ackFromSipID, string ackToSipId, out string idInDialogWith, out bool isGroupCall)
        {
            // We received an Invite, sent Ok and now we receive ack
            idInDialogWith = ackFromSipID;
            // Check if is a Simoco group invite
            isGroupCall = false;
            if (ackToSipId != _sipClient.Username)
            {
                isGroupCall = true;
                idInDialogWith = ackToSipId;
            }
        }

        /// <summary>
        /// Save the message in a dictionary because it has to be resent to the radio when we acknowledge the alarm
        /// </summary>
        /// <param name="senderID">The sender</param>
        /// <param name="alarmInfo">The body of the alarm message</param>
        protected void AddSimocoAlarmToDictionary(string senderID, string alarmInfo)
        {
            _simocoID_emergencyStatusReport_dict[senderID] = alarmInfo;
        }

        /// <summary>
        /// Checks if the ping response is valid and handles the ping data dictionary
        /// </summary>
        /// <param name="senderID">The sender id</param>
        /// <param name="pingData">The ping data</param>
        /// <returns>True if the ping response is valid, else false</returns>
        protected bool HandleSimocoPingResponse(string senderID, byte[] pingData)
        {
            bool returnValue = false;
            if (_ID_pingBytest_timer_dict.ContainsKey(senderID))
            {
                if (Enumerable.SequenceEqual(pingData, _ID_pingBytest_timer_dict[senderID].Item1))
                {
                    _ID_pingBytest_timer_dict[senderID].Item2.Stop();
                    _ID_pingBytest_timer_dict.Remove(senderID);

                    returnValue = true;
                }
            }

            return returnValue;
        }

        private byte GenerateNewTSN()
        {
            // TSN are doar 7 biti, al optulea este rezervat pentru L (pare a fi 0 pentru Simoco)
            // Deci TSN poate fi maxim 0111 1111 = 7F = 127
            return (byte)_rand.Next(128);
        }

        private int ReturnAvailablePort()
        {
            lock (_lockerRtpPort)
            {
                int rtpPort = MinRtpPortNumber;
                while (
                    (IsPortAllreadyInUse(rtpPort) || PortNumerProposedInSentInvites(rtpPort))
                    && rtpPort < MaxRtpPortNumber)
                {
                    rtpPort += 2;
                }
                if (rtpPort < MaxRtpPortNumber)
                    return rtpPort;
                else
                    throw new SipClassException(
                        string.Format("Nu gasesc port liber in range-ul {0} - {1}", MinRtpPortNumber, MaxRtpPortNumber));
            }
        }

        private bool PortNumerProposedInSentInvites(int portNb)
        {
            Invite inv = _IDsentInviteDict.Values.FirstOrDefault((invite) =>
            {
                return invite.SessionDescription.Media[0].Port == portNb;
            });
            if (inv != null)
                return true;
            else
                return false;
        }

        private bool IsPortAllreadyInUse(int portNumber)
        {

            return (from p in System.Net.NetworkInformation.IPGlobalProperties.GetIPGlobalProperties().GetActiveUdpListeners()
                    where p.Port == portNumber
                    select p).Count() == 1;
        }

        /// <summary>
        /// Checks if an integer can be used as a rtp port
        /// </summary>
        /// <param name="rtpPort">The integer to be cecked</param>
        /// <returns>True if is a valid rtp port, else false</returns>
        public static bool ValidRtpPort(int rtpPort)
        {
            if (rtpPort < 1024 || rtpPort > 65534)
            {
                return false;
            }
            else if (rtpPort % 2 == 1)
            {
                return false;
            }
            else
                return true;
        }

        private Byte[] GenerateNmea(double latitude, double longitude, double speed, DateTime timeUtc)
        {
            #region variables declaration

            byte crypted = 0;
            byte Q = 1;
            Byte[] result = new Byte[10];
            byte latitudeDegrees, latitudeMinutes;
            byte longitudeDegrees, longitudeMinutes;

            #endregion variables declaration

            #region latitude

            sbyte NS = (latitude > 0) ? (sbyte)1 : (sbyte)0;
            latitude = (latitude > 0) ? latitude : latitude * (-1);
            latitudeDegrees = (byte)Math.Truncate(latitude);
            double latFractionPartMinutes = (latitude - latitudeDegrees) * 60;
            latitudeMinutes = (byte)Math.Truncate(latFractionPartMinutes);
            double difflat = latFractionPartMinutes - Math.Truncate(latFractionPartMinutes);

            ushort latitudeFractionOfMin = 0;
            if (difflat.ToString().Split(Convert.ToChar(CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator)).Count() > 1)
            {
                string difflat1 = difflat.ToString().Split(Convert.ToChar(CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator))[1];
                latitudeFractionOfMin = Convert.ToUInt16(difflat1.Length > 4 ? difflat1.Substring(0, 4) : difflat1.Substring(0, difflat1.Length - 1));
            }
            #endregion latitude

            #region longitude

            sbyte EW = (longitude > 0) ? (sbyte)1 : (sbyte)0;
            longitude = (longitude > 0) ? longitude : longitude * (-1);
            longitudeDegrees = (byte)Math.Truncate(longitude);
            double lngFractionPartMinutes = (longitude - longitudeDegrees) * 60;
            longitudeMinutes = (byte)Math.Truncate(lngFractionPartMinutes);
            double difflng = lngFractionPartMinutes - Math.Truncate(lngFractionPartMinutes);
            ushort longitudeFractionOfMin = 0;
            if (difflng.ToString().Split(Convert.ToChar(CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator)).Count() > 1)
            {
                string difflng1 = difflng.ToString().Split(Convert.ToChar(CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator))[1];
                longitudeFractionOfMin = Convert.ToUInt16(difflng1.Length > 4 ? difflng1.Substring(0, 4) : difflng1.Substring(0, difflng1.Length - 1));
            }
            #endregion longitude

            #region speed

            // viteza in knotes
            byte speed_knots = Convert.ToByte(speed / 1.852);
            #endregion speed

            #region time

            // time as unix time
            byte hours = (byte)timeUtc.Hour;
            byte minutes = (byte)timeUtc.Minute;
            byte ten_sec = (byte)(timeUtc.Second / 10);

            #endregion time

            #region compute byte array

            // | C NS EW Q speed speed speed speed | speed speed speed ndeg ndeg ndeg ndeg ndeg | ndeg ndeg nmin nmin nmin nmin nmin nmin |
            // |       byte 0                      |                 byte 1                     |            byte 2
            result[0] = (byte)((crypted << 7) | (NS << 6) | (EW << 5) | (Q << 4) | (speed_knots >> 3) /*& 0x07*/);
            result[1] = (byte)((speed_knots << 5) /*& 0x1F*/ | (latitudeDegrees >> 2) /*& 0x0F*/);
            result[2] = (byte)((latitudeDegrees << 6) /*& 0x3F*/ | latitudeMinutes);

            // | nminf nminf nminf nminf nminf nminf nminf nminf | nminf nminf nminf nminf nminf nminf edeg edeg |
            // |                byte 3                           |                 byte 4                        |
            byte[] latitudeFractionOfMinBytes = BitConverter.GetBytes(latitudeFractionOfMin);
            if (BitConverter.IsLittleEndian)
                Array.Reverse(latitudeFractionOfMinBytes);

            result[3] = (byte)((latitudeFractionOfMinBytes[0] << 2) | (latitudeFractionOfMinBytes[1] >> 6));
            result[4] = (byte)((latitudeFractionOfMinBytes[1] << 2) | (longitudeDegrees >> 6));

            // | edeg edeg edeg edeg edeg edeg eminmm eminmm | eminmm eminmm eminmm eminmm eminf eminf eminf eminf |
            // |                byte 5                       |                 byte 6                              |
            result[5] = (byte)((longitudeDegrees << 2) | (longitudeMinutes >> 4));
            byte[] longitudeFractionOfMinBytes = BitConverter.GetBytes(longitudeFractionOfMin);
            if (BitConverter.IsLittleEndian)
                Array.Reverse(longitudeFractionOfMinBytes);
            result[6] = (byte)((longitudeMinutes << 4) | (longitudeFractionOfMinBytes[0] >> 2));

            // | eminf eminf eminf eminf eminf eminf eminf eminf | eminf eminf h h h h h m | m m m m m s s s |
            // |                byte 7                           |        byte 8           |    byte 9       |
            result[7] = (byte)((longitudeFractionOfMinBytes[0] << 6) | (longitudeFractionOfMinBytes[1] >> 2));
            result[8] = (byte)((longitudeFractionOfMinBytes[1] << 6) | (hours << 1) | (minutes >> 5));
            result[9] = (byte)((minutes << 3) | ten_sec);

            #endregion compute byte array

            return result;
        }

        private string GetLocalAddresOnNetworkWith(IPAddress ipAddress)
        {
            foreach (NetworkInterface networkAdapter in NetworkInterface.GetAllNetworkInterfaces())
            {
                if (networkAdapter.OperationalStatus == OperationalStatus.Up)
                {
                    foreach (UnicastIPAddressInformation ip in networkAdapter.GetIPProperties().UnicastAddresses)
                    {

                        if (ip.Address.AddressFamily == AddressFamily.InterNetwork)
                        {
                            if (IsInSameSubnet(ip.Address, ipAddress, ip.IPv4Mask))
                                return ip.Address.ToString();
                        }
                    }
                }
            }
            throw new SipClassException(string.Format("No ip address that could comunicate with AIS Gateway: {0}", ipAddress));
        }

        /// <summary>
        /// Determines the most appropriate local end point to contact the provided remote end point. 
        /// Testing shows this method takes on average 1.6ms to return.
        /// </summary>
        /// <param name="remoteIPEndPoint">The remote end point</param>
        /// <returns>The selected local end point</returns>
        private static IPEndPoint BestLocalEndPoint(IPEndPoint remoteIPEndPoint)
        {
            Socket testSocket = new Socket(remoteIPEndPoint.AddressFamily, SocketType.Dgram, System.Net.Sockets.ProtocolType.Udp);
            testSocket.Connect(remoteIPEndPoint);
            return (IPEndPoint)testSocket.LocalEndPoint;
        }









        private bool IsInSameSubnet(IPAddress address2, IPAddress address, IPAddress subnetMask)
        {
            IPAddress network1 = GetNetworkAddress(address, subnetMask);
            IPAddress network2 = GetNetworkAddress(address2, subnetMask);

            return network1.Equals(network2);
        }

        private IPAddress GetNetworkAddress(IPAddress address, IPAddress subnetMask)
        {
            byte[] ipAdressBytes = address.GetAddressBytes();
            byte[] subnetMaskBytes = subnetMask.GetAddressBytes();

            if (ipAdressBytes.Length != subnetMaskBytes.Length)
                throw new ArgumentException("Lengths of IP address and subnet mask do not match.");

            byte[] broadcastAddress = new byte[ipAdressBytes.Length];
            for (int i = 0; i < broadcastAddress.Length; i++)
            {
                broadcastAddress[i] = (byte)(ipAdressBytes[i] & (subnetMaskBytes[i]));
            }
            return new IPAddress(broadcastAddress);
        }

        private string AddMsgLenForMBus(string textToSend)
        {
            String cmdok = textToSend;
            Int32 tmp = cmdok.Length + 1;
            tmp += tmp.ToString().Length;
            String TMPcmdok = "#" + tmp.ToString() + cmdok;
            if (tmp != TMPcmdok.Length) cmdok = "#" + TMPcmdok.Length + cmdok;
            else cmdok = TMPcmdok;
            return cmdok;
        }

        private DateTime UnixTimeStampToDateTime(double unixTimeStamp)
        {
            // Unix timestamp is seconds past epoch
            System.DateTime dtDateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0);
            dtDateTime = dtDateTime.AddSeconds(unixTimeStamp);
            return dtDateTime;
        }

        private double DateTimeToUnixTime(DateTime utcTime)
        {
            System.DateTime baseTime = new DateTime(1970, 1, 1, 0, 0, 0, 0);
            return (utcTime - baseTime).TotalSeconds;
        }

        #endregion

        #region Events
        /// <summary>
        /// Occurs when you send an invite to a sip id
        /// </summary>
        public event EventHandler<SipEventArgs> InviteSent;
        /// <summary>
        /// Occurs when you cancel a sent invite
        /// </summary>
        public event EventHandler<SipEventArgs> InviteSentCanceled;
        /// <summary>
        /// Occurs when you receive an invite
        /// </summary>
        public event EventHandler<InviteReceivedArgs> InviteReceived;
        /// <summary>
        /// Occurs when an invite is cancelled before you had time to accept or reject it.
        /// </summary>
        public event EventHandler<SipEventArgs> InviteReceivedCanceled;
        /// <summary>
        /// Occurs when you decline an invite from another user
        /// </summary>
        public event EventHandler<SipEventArgs> InviteReceivedDeclined;
        /// <summary>
        /// An error occured while attempting to establish a voice session
        /// </summary>
        public event EventHandler<ErrorEventArgs> ErrorOnCreatingDialog;
        /// <summary>
        /// Occurs when a voice session (a dialog) has been established
        /// </summary>
        public event EventHandler<DialogCreatedEventArgs> DialogCreated;
        /// <summary>
        /// Occurs when a voice session (a dialog) is closed
        /// </summary>
        public event EventHandler<DialogClosedEventArgs> DialogClosed;
        /// <summary>
        /// Ocurs when a voice buffer is received from a sip id
        /// </summary>
        public event EventHandler<AudioEventArgs> VoiceReceived;
        /// <summary>
        /// Ocurs when you send the maximum number of PTT requests and you do not receive an answer
        /// </summary>
        protected event EventHandler<SipEventArgs> PTTrequestFailed;
        /// <summary>
        /// Ocurs when your PTT request is denied
        /// </summary>
        protected event EventHandler<SipEventArgs> PTTrequestDenied;
        /// <summary>
        /// Occurs when your PTT request is accepted
        /// </summary>
        protected event EventHandler<SipInfoEventArgs> PTTrequestGranted;
        /// <summary>
        /// Occurs when you receive a PTT request
        /// </summary>
        protected event EventHandler<PTTrequestEventArgs> PTTrequestReceived;
        /// <summary>
        /// Occurs when you receive a PTT Start packet
        /// </summary>
        protected event EventHandler<RtpEventArgs> PTTStartReceived;
        /// <summary>
        /// Occurs when you receive a PTT End packet
        /// </summary>
        protected event EventHandler<RtpEventArgs> PTTEndReceived;
        /// <summary>
        /// Occurs when you receive an sms
        /// </summary>
        public event EventHandler<SmsReceivedEventsArgs> SmsReceived;

        /*
        /// <summary>
        /// Represents the method that will handle the RegistrationStateChanged event
        /// </summary>
        /// <param name="sender">A reference to SipClientClass that generated the event</param>
        /// <param name="registeredID">The registered sip id</param>
        /// <param name="reason"></param>
        public delegate void RegistrationStateChangedDelegate(object sender, string registeredID, RegistrationStatus reason);
        */

        /// <summary>
        /// Occurs when the sip registration status changes
        /// </summary>
        public event EventHandler<RegistrationStateChangedEventArgs> RegistrationStateChanged;
        /// <summary>
        /// Occurs when a GPS report is received from a Simoco radio
        /// </summary>
        protected event EventHandler<GpsDataEventArgs> SimocoGpsReportReceived;
        /// <summary>
        /// Occurs when a GPS report is received from a Linx device
        /// </summary>
        protected event EventHandler<LinxGpsDataEventArgs> LinxGpsReportReceived;
        /// <summary>
        /// Occurs when a periodically GPS report is received
        /// </summary>
        public event EventHandler<GpsDataEventArgs> GpsPeriodicallyReportReceived;
        /// <summary>
        /// Occurs when a Simoco radio responds to a ping request
        /// </summary>
        protected event EventHandler<SipEventArgs> SimocoPingResponseReceived;
        /// <summary>
        /// Occurs when a Simoco radio fails to respond to a ping request
        /// </summary>
        protected event EventHandler<SipEventArgs> SimocoPingRequestFailed;
        /// <summary>
        /// Occurs when a Simoco radio sends a status report
        /// </summary>
        protected event EventHandler<SimocoDeviceStatusReportEventArgs> SimocoStatusReportReceived;
        /// <summary>
        /// Occurs when an emergency alarm is received from a Linx device
        /// </summary>
        protected event EventHandler<Linx.LinxEmergencyAlarmReceivedEventArgs> LinxEmergencyAlarmReceived;
        /// <summary>
        /// Occurs when an Ars command is received from a Linx device
        /// </summary>
        protected event EventHandler<Linx.ArsReceivedEventArgs> LinxArsReceived;
      

        private void OnInviteSent(SipEventArgs e)
        {
            EventHandler<SipEventArgs> handler = InviteSent;
            if (handler != null)
                handler(this, e);
        }

        private void OnInviteSentCanceled(SipEventArgs e)
        {
            EventHandler<SipEventArgs> handler = InviteSentCanceled;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// This is the method that raises the ErrorOnCreatingDialog event
        /// </summary>
        /// <param name="e">Data for the ErrorOnCreatingDialog event</param>
        /// <remarks>Do not forget to call the base version when overrinding, 
        /// <para>otherwize the ErrorOnCreatingDialog event will not fire</para>
        /// </remarks>
        protected virtual void OnError(ErrorEventArgs e)
        {
            EventHandler<ErrorEventArgs> handler = ErrorOnCreatingDialog;
            if (handler != null)
                handler(this, e);
        }

        private void OnInviteReceived(InviteReceivedArgs e)
        {
            EventHandler<InviteReceivedArgs> handler = InviteReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnInviteReceivedCanceled(SipEventArgs e)
        {
            EventHandler<SipEventArgs> handler = InviteReceivedCanceled;
            if (handler != null)
                handler(this, e);
        }

        private void OnInviteReceivedDeclined(SipEventArgs e)
        {
            EventHandler<SipEventArgs> handler = InviteReceivedDeclined;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// This is the method that raises the DialogCreated event
        /// </summary>
        /// <param name="e">Data for the DialogCreatedEvent</param>
        /// <remarks>Do not forget to call the base version when overrinding, 
        /// <para>otherwize the DialogCreated Event will not fire</para>
        /// </remarks>
        protected virtual void OnDialogCreated(DialogCreatedEventArgs e)
        {
            EventHandler<DialogCreatedEventArgs> handler = DialogCreated;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// This is the method that raises the DialogClosed event
        /// </summary>
        /// <param name="e">Data for the DialogClosed event</param>
        /// <remarks>Do not forget to call the base version when overrinding, 
        /// <para>otherwize the DialogClosed Event will not fire</para>
        /// </remarks>
        protected virtual void OnDialogClosed(DialogClosedEventArgs e)
        {
            EventHandler<DialogClosedEventArgs> handler = DialogClosed;
            if (handler != null)
            {
                handler(this, e);
            }
        }

        /// <summary>
        /// This is the method that raises the VoiceReceived event
        /// </summary>
        /// <param name="e">Data for the VoiceReceived event</param>
        /// <remarks>Do not forget to call the base version when overrinding,
        /// <para>otherwise the VoiceReceived Event will not fire</para>
        /// </remarks>
        protected virtual void OnVoiceReceived(AudioEventArgs e)
        {
            EventHandler<AudioEventArgs> handler = VoiceReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnPTTrequestFailed(string sipIDinDialogWith)
        {
            EventHandler<SipEventArgs> handler = PTTrequestFailed;
            if (handler != null)
                handler(this, new SipEventArgs(sipIDinDialogWith));
        }

        private void OnPTTrequestDenied(string sipIDinDialogWith)
        {
            EventHandler<SipEventArgs> handler = PTTrequestDenied;
            if (handler != null)
                handler(this, new SipEventArgs(sipIDinDialogWith));
        }

        private void OnPTTrequestGranted(string sipID, bool isGroup)
        {
            EventHandler<SipInfoEventArgs> handler = PTTrequestGranted;
            if (handler != null)
                handler(this, new SipInfoEventArgs(sipID, isGroup));
        }

        private void OnPTTrequestReceived(PTTrequestEventArgs e)
        {
            EventHandler<PTTrequestEventArgs> handler = PTTrequestReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnPTTStartReceived(RtpEventArgs e)
        {
            EventHandler<RtpEventArgs> handler = PTTStartReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnPTTEndReceived(RtpEventArgs e)
        {
            EventHandler<RtpEventArgs> handler = PTTEndReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnRegistrationStateChanged(RegistrationStateChangedEventArgs e)
        {
            EventHandler<RegistrationStateChangedEventArgs> handler = RegistrationStateChanged;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// Raises the SmsReceived event
        /// </summary>
        /// <param name="e">Data for the event</param>
        protected void OnSmsReceived(SmsReceivedEventsArgs e)
        {
            EventHandler<SmsReceivedEventsArgs> handler = SmsReceived;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// Raises the SimocoGpsReportReceived event
        /// </summary>
        /// <param name="e">Data for the Gps event</param>
        protected void OnSimocoGpsReportReceived(GpsDataEventArgs e)
        {
            EventHandler<GpsDataEventArgs> handler = SimocoGpsReportReceived;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// Raises the GpsPeriodicallyReportReceived event
        /// </summary>
        /// <param name="e">Data for the Gps event</param>
        protected void OnGpsPeriodicallyReportReceived(GpsDataEventArgs e)
        {
            EventHandler<GpsDataEventArgs> handler = GpsPeriodicallyReportReceived;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// Raises SimocoPingResponseReceived event
        /// </summary>
        /// <param name="e">Data about the event</param>
        protected void OnSimocoPingResponseReceived(SipEventArgs e)
        {
            EventHandler<SipEventArgs> handler = SimocoPingResponseReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnSimocoPingRequestFailed(SipEventArgs e)
        {
            EventHandler<SipEventArgs> handler = SimocoPingRequestFailed;
            if (handler != null)
                handler(this, e);
        }

        /// <summary>
        /// Raises the SimocoStatusReportReceived event
        /// </summary>
        /// <param name="e">Data for the event</param>
        protected void OnSimocoStatusReportReceived(SimocoDeviceStatusReportEventArgs e)
        {
            EventHandler<SimocoDeviceStatusReportEventArgs> handler = SimocoStatusReportReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnLinxEmergencyAlarmReceived(Linx.LinxEmergencyAlarmReceivedEventArgs e)
        {
            EventHandler<Linx.LinxEmergencyAlarmReceivedEventArgs> handler = LinxEmergencyAlarmReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnLinxGpsReportReceived(LinxGpsDataEventArgs e)
        {
            EventHandler<LinxGpsDataEventArgs> handler = LinxGpsReportReceived;
            if (handler != null)
                handler(this, e);
        }

        private void OnLinxArsReceived(Linx.ArsReceivedEventArgs e)
        {
            EventHandler<Linx.ArsReceivedEventArgs> handler = LinxArsReceived;
            if (handler != null)
                handler(this, e);
        }

        #endregion



    }

    /// <summary>
    /// Provides data about a sip related event
    /// </summary>
    public class SipEventArgs : EventArgs
    {
        /// <summary>
        /// Contains the id of the sip user that we are in dialog with
        /// </summary>
        public string SipIDinDialogWith { get; private set; }
        internal SipEventArgs(string sipIDinDialogWith)
        {
            SipIDinDialogWith = sipIDinDialogWith;
        }
    }


    public class SipInfoEventArgs : SipEventArgs
    {
        public bool IsGroup { get; private set; }
        internal SipInfoEventArgs(string sipIdInDialogWith, bool isGroup) 
            : base(sipIdInDialogWith)
        {
            IsGroup = isGroup;
        }
    }

    /// <summary>
    /// Provides data about the message bus related events 
    /// </summary>
    public class MBusEventArgs : SipEventArgs
    {
        /// <summary>
        /// The sequence id
        /// </summary>
        public string SeqID { get; private set; }
        internal MBusEventArgs(string sipIDinDialogWith, string seqID) : 
            base(sipIDinDialogWith)
        {
            SeqID = seqID;
        }
    }

   
    /// <summary>
    /// Provides data about a RTP related event
    /// </summary>
    public class RtpEventArgs : SipEventArgs
    {
        /// <summary>
        /// The sip ID of the user sending the RTP packet
        /// </summary>
        public string SipIDsendingRTP { get; private set; }
        internal RtpEventArgs(string sipIDinDialogWith, string sipIDsendingRTP) : 
            base(sipIDinDialogWith)
        {
            SipIDsendingRTP = sipIDsendingRTP;
        }
    }
    /// <summary>
    /// Provides data for the InviteReceived event
    /// </summary>
    public class InviteReceivedArgs : SipEventArgs
    {
        /// <summary>
        /// Contains the sip id that sends the invite
        /// </summary>
        public string SipIDsendingInvite { get; private set; }
        /// <summary>
        /// True if is an emergency call, else false
        /// </summary>
        public bool IsEmergencyCall { get; private set; }
        internal InviteReceivedArgs(string sipIDinDialogWith, string sipIDsendingInvite, TypeOfCall typeOfCall, bool isEmergencyCall = false) :
            base(sipIDinDialogWith)
        {
            SipIDsendingInvite = sipIDsendingInvite;
            IsEmergencyCall = isEmergencyCall;
            TypeOfCall = typeOfCall;
        }

        /// <summary>
        /// Gets the type of call: Full or half duplex
        /// </summary>
        public TypeOfCall TypeOfCall { get; private set; }
    }
    /// <summary>
    /// Provides data for the DialogClosed event
    /// </summary>
    public class DialogClosedEventArgs : SipEventArgs
    {
        /// <summary>
        /// The sip id who closed the dialog
        /// </summary>
        public string SipIDwhoClosed { get; private set; }
        /// <summary>
        /// The reason for dialog closing
        /// </summary>
        public DialogClosedReason Reason { get; private set; }

        public bool WasGroupCall { get; private set; }
        internal DialogClosedEventArgs(string sipIDinDialogWith, string sipIDWhoClosed, bool wasGroupCall, DialogClosedReason reason) : 
            base(sipIDinDialogWith)
        {
            SipIDwhoClosed = sipIDWhoClosed;
            WasGroupCall = wasGroupCall;
            Reason = reason;
        }
    }
    /// <summary>
    /// Provides data for the ErrorOnCreatingDialog event
    /// </summary>
    public class ErrorEventArgs : EventArgs
    {
        /// <summary>
        /// Reason for the error
        /// </summary>
        public string Reason { get; private set; }
        /// <summary>
        /// The sip ID who sent the invite
        /// </summary>
        public string FromID { get; private set; }
        /// <summary>
        /// The sip ID who received the invite
        /// </summary>
        public string ToID { get; private set; }
        internal ErrorEventArgs(string toID, string fromID, string reason)
        {
            Reason = reason;
            FromID = fromID;
            ToID = toID;
        }
    }

    /// <summary>
    /// Provides data for the RegistrationStateChanged event
    /// </summary>
    public class RegistrationStateChangedEventArgs : EventArgs
    {
        /// <summary>
        /// The registered ID
        /// </summary>
        public string RegisteredId { get; private set; }

        /// <summary>
        /// The registration status changed that is the reason for this event
        /// </summary>
        public RegistrationStatus Reason { get; private set; }

        internal RegistrationStateChangedEventArgs(string registeredId, RegistrationStatus reason)
        {
            RegisteredId = registeredId;
            Reason = reason;
        }
    }

    /// <summary>
    /// Provides data for the DialogCreated event
    /// </summary>
    public class DialogCreatedEventArgs : EventArgs
    {
        /// <summary>
        /// The sip ID who sent the invite
        /// </summary>
        public string FromID { get; private set; }
        /// <summary>
        /// The sip ID who received the invite
        /// </summary>
        public string ToID { get; private set; }
        /// <summary>
        /// True if is a group call, else false
        /// </summary>
        public bool IsGroupCall { get; private set; }
        /// <summary>
        /// Returns the type of dialog: full or half-duplex
        /// </summary>
        public TypeOfCall TypeOfDialog { get; private set; }
        internal DialogCreatedEventArgs(string toID, string fromID, TypeOfCall typeOfDialog, bool isGroupCall)
        {
            FromID = fromID;
            ToID = toID;
            TypeOfDialog = typeOfDialog;
            IsGroupCall = isGroupCall;
        }
    }

    /// <summary>
    /// Provides data for the PTTrequestReceived event
    /// </summary>
    public class PTTrequestEventArgs : RtpEventArgs
    {
        /// <summary>
        /// <para>Gets or sets a value indicating whether the PTT request should be accepted or denied</para>
        /// <para>The default value is null, meaning that no response is sent (yet)</para>
        /// </summary>
        public bool? Grant { get; set; }
        internal PTTrequestEventArgs(string sipIDinDialogWith)
            : base(sipIDinDialogWith, sipIDinDialogWith)
        {
            Grant = null;
        }
    }
    /// <summary>
    /// Provides data for the SmsReceived event
    /// </summary>
    public class SmsReceivedEventsArgs : RtpEventArgs
    {
        /// <summary>
        /// The sms text
        /// </summary>
        public string Message { get; private set; }
        internal SmsReceivedEventsArgs(string sipIDinDialogWith, string message)
            : base(sipIDinDialogWith, sipIDinDialogWith)
        {
            Message = message;
        }
    }

    /// <summary>
    /// Provides data for the GPS related events
    /// </summary>
    public class GpsDataEventArgs : SipEventArgs
    {
        /// <summary>
        /// Latitude
        /// </summary>
        public double Latitude { get; private set; }
        /// <summary>
        /// Longitude
        /// </summary>
        public double Longitude { get; private set; }
        /// <summary>
        /// Speed
        /// </summary>
        public double Speed { get; private set; }
        /// <summary>
        /// Utc time
        /// </summary>
        public DateTime Time { get; private set; }
        

        internal GpsDataEventArgs(string sipIDinDialogWith, double latitude, double longitude, double speed, DateTime time)
            :base(sipIDinDialogWith)
        {
            Latitude = latitude;
            Longitude = longitude;
            Speed = speed;
            Time = time;
        }
    }

    /// <summary>
    /// Provides data for the LinxGpsReportReceived event
    /// </summary>
    public class LinxGpsDataEventArgs : GpsDataEventArgs
    {
        /// <summary>
        /// Contains the sequence id
        /// </summary>
        public string SeqID { get; private set; }
        internal LinxGpsDataEventArgs(string sipIDinDialogWith, string seqID, double latitude, double longitude, double speed, DateTime time)
            :base(sipIDinDialogWith, latitude, longitude, speed, time)
        {
            SeqID = seqID;
        }
    }

    /// <summary>
    /// Provides data for the SimocoStatusReportReceived event 
    /// </summary>
    public class SimocoDeviceStatusReportEventArgs : SipEventArgs
    {
        /// <summary>
        /// Latitude
        /// </summary>
        public double Latitude { get; private set; }
        /// <summary>
        /// Longitude
        /// </summary>
        public double Longitude { get; private set; }
        /// <summary>
        /// Type of Alarm
        /// </summary>
        public Simoco.AlarmType AlarmType { get; private set; }

        internal SimocoDeviceStatusReportEventArgs(string sipIDinDialogWith, double latitude, double longitude, Simoco.AlarmType alarmType)
            :base(sipIDinDialogWith)
        {
            Latitude = latitude;
            Longitude = longitude;
            AlarmType = alarmType;
        }
    }

    internal class RegistrationData
    {
        /// <summary>
        /// Interval to send sip registration requests. Value is in seconds
        /// </summary>
        internal int Expires { get; private set; }
        /// <summary>
        /// Sip ID to register
        /// </summary>
        internal string SipID { get; private set; }
        internal bool SimocoGroupRegistration { get; private set; }

        internal RegistrationData(string sipID, int expires, bool simocoGroupRegistration = false)
        {
            SipID = sipID;
            Expires = expires;
            SimocoGroupRegistration = simocoGroupRegistration;
        }
    }

    /// <summary>
    /// Contains a list of audio formats
    /// </summary>
    public enum AudioFormat
    {
        /// <summary>
        /// Pulse-code modulation, the standard format (used by Safedispatch)
        /// </summary>
        PCM,
        /// <summary>
        /// The G.711 codec, ALAW type (or PCMA), used by the RTP protocol
        /// </summary>
        PCMA
    }

    /// <summary>
    /// Contains a list of sip registration statuses
    /// </summary>
    public enum RegistrationStatus
    {
        /// <summary>
        /// Registered to sip server
        /// </summary>
        Registered,
        /// <summary>
        /// Not registered to sip server
        /// </summary>
        NotRegistered,
        /// <summary>
        /// Register request did not get to the sip server
        /// </summary>
        RequestTimeout,
        /// <summary>
        /// User credentials are wrong
        /// </summary>
        WrongCredentials,
        /// <summary>
        /// Not registered becouse an Unregister request was sent to the sip server
        /// </summary>
        UnregisteredAtRequest,
        /// <summary>
        /// The initial value, registration procedure not started
        /// </summary>
        RegistrationNotStarted,
        /// <summary>
        /// Error in IndependentSoft library
        /// </summary>
        SocketError
    }

    /// <summary>
    /// Contains a list of reasons for closing a sip dialog
    /// </summary>
    public enum DialogClosedReason
    {
        /// <summary>
        /// Sip Bye was received or sent
        /// </summary>
        NormalClosing,
        /// <summary>
        /// The interval the dialog is maintained without voice transmision has passed
        /// </summary>
        TimerHangTimeExpired,
        /// <summary>
        /// Rtp packet was sent to a closed port
        /// </summary>
        Error,
        /// <summary>
        /// The interval the dialog is maintained without receiving heartbeat has passed
        /// </summary>
        TimerAliveTimeExpired
    }
    /// <summary>
    /// The exception that is thrown when there is an error in the SipClient class 
    /// </summary>
    [Serializable]
    public class SipClassException : Exception
    {
        public SipClassException() { }
        public SipClassException(string message) : base(message) { }
        public SipClassException(string message, Exception inner) : base(message, inner) { }
        protected SipClassException(
            System.Runtime.Serialization.SerializationInfo info,
            System.Runtime.Serialization.StreamingContext context)
            : base(info, context) { }
    }
}