We’re having problems with outbound, off net calls going trough PSTN gateway of our service provider. All outgoing calls are successfully established but disconnected after some 30s. Collected SIP traces show that in case of outbound calls PSTN gateway of our service provider, immediately after sending 200 OK response to initial INVITE, sends subsequent re-INVITE massage trying to change UPD port. As our Asterisk doesn’t respond to that new request call is disconnected, after some 30 seconds.
The question is how we can make Asterisk (deployed version is Asterisk PBX 126.96.36.199) capable of responding to re-INVITE request coming from SP’s side?