private void Handle2xx(SIP_Dialog dialog, SIP_ServerTransaction transaction)
{
if (dialog == null)
{
throw new ArgumentNullException("dialog");
}
if (transaction == null)
{
throw new ArgumentException("transaction");
}
/* RFC 6026 8.1.
Once the response has been constructed, it is passed to the INVITE
server transaction. In order to ensure reliable end-to-end
transport of the response, it is necessary to periodically pass
the response directly to the transport until the ACK arrives. The
2xx response is passed to the transport with an interval that
starts at T1 seconds and doubles for each retransmission until it
reaches T2 seconds (T1 and T2 are defined in Section 17).
Response retransmissions cease when an ACK request for the
response is received. This is independent of whatever transport
protocols are used to send the response.
If the server retransmits the 2xx response for 64*T1 seconds without
receiving an ACK, the dialog is confirmed, but the session SHOULD be
terminated. This is accomplished with a BYE, as described in Section
15.
T1 - 500
T2 - 4000
*/
TimerEx timer = null;
EventHandler<SIP_RequestReceivedEventArgs> callback = delegate(object s1, SIP_RequestReceivedEventArgs e)
{
try
{
if (e.Request.RequestLine.Method == SIP_Methods.ACK)
{
// ACK for INVITE 2xx response received, stop retransmitting INVITE 2xx response.
if (transaction.Request.CSeq.SequenceNumber == e.Request.CSeq.SequenceNumber)
{
if (timer != null)
{
timer.Dispose();
}
}
}
}
catch
{
// We don't care about errors here.
}
};
dialog.RequestReceived += callback;
// Create timer and sart retransmitting INVITE 2xx response.
timer = new TimerEx(500);
timer.AutoReset = false;
timer.Elapsed += delegate(object s, System.Timers.ElapsedEventArgs e)
{
try
{
lock (transaction.SyncRoot)
{
if (transaction.State == SIP_TransactionState.Accpeted)
{
transaction.SendResponse(transaction.FinalResponse);
}
else
{
timer.Dispose();
return;
}
}
timer.Interval = Math.Min(timer.Interval * 2, 4000);
timer.Enabled = true;
}
catch
{
// We don't care about errors here.
}
};
timer.Disposed += delegate(object s1, EventArgs e1)
{
try
{
dialog.RequestReceived -= callback;
}
catch
{
// We don't care about errors here.
}
};
timer.Enabled = true;
}
