Use SIP OPTIONS instead of EMPTY message for keep-alive.
With the rport information in the response of SIP OPTIONS request,
we are able to know if the NAT port mapping is changed if a device
is behind a NAT router. If the mapping is changed, we will trigger
the registration and set the maximum keep-alive interval measured
for the keepalive process.
+fix setRPort() in NIST SIP stack for compatibility.
+fix the WakupTimer in recaculation of the events.
Change-Id: Ifdb8b5d6fd25d69cb0a1520b23b783000b4f6029
6 files changed