2011/4/28 Klaus Darilion klaus.mailinglists@pernau.at:
IIRC we recently had a discussion about SIP outbound [1] and the benefits of an implementation in Kamailio. Just playing around with a SIP client on an iphone I discovered a usecase. Whenever the iphone gets a new IP address (quite often as it often changes between WiFi and 3G) the client reREGISTERs with the new IP address (establishing a new TCP connection). This leads to lots of "broken" registrations and TCP connections [2].
...which is UGLY !!! as it causes annoying timeouts due to the false parallel forking.
By use of SIP outbound and re-registration using the same "reg-id" the proxy would be able to replace the old registration with the new registration. Further, if Kamailio would have a mapping from registrations to TCP connections it could also close the dead TCP connections.
Yes. I know that the IETF produces lot of garbage, but RFC 5626 (Managing Client-Initiated Connections) is a good stuff (and needed, specially in SIP scenarios which mobile clients).