[pjsip] redirection (status 302) issue with tcp transport

[Neil Ostroff]

Hello.

I have encountered an issue with redirection (i.e., processing a 302 status
message) in the pjsua application and was hoping for a suggestion on how to
proceed. The problem occurs after initiating a new call (i.e., being a UAC)
using TCP transport and receiving a status 302 with a contact header
containing transport=tcp. The new invite uses udp transport (i.e., the tcp
transport parameter is being ignored). If I force the use of TCP by
disabling UDP, the trace output shows the following:

19:55:46.082    tsx00D3AFAC  Failed to send Request msg INVITE/cseq=12709
(tdta00D35618)! err=171060 (Unsupported transport (PJSIP_EUNSUPTRANSPORT))
19:55:46.082    pjsua_app.c  Call 0 is DISCONNECTED [reason=503 (Unsupported
transport (PJSIP_EUNSUPTRANSPORT))]