Very strange behavior Cisco GW on SIP incoming call

[Vadim Semenov]

Hi, colleagues,

I have following trouble - i call on DISA (on the CME router) and i hear welcome message, after that i press short number of customer and i hear Ringing, but when calling number answer - i don't hear him and after 2 sec call is dropped.

Please see following SIP trace diag:

Why Cisco Gateway 2951 send INVITE to ITSP when calling customer answer ?

[Vivek Batra]

That INVITE is probably sent in the same dialog to negotiate again some media related parameters. Since call is being dropped by CUCM, I doubt it has anything to do with in-dialog INVITE. Can you please share the SIP traces on both the call legs to see if there is any issue at SIP level....

- Vivek

[Vadim Semenov]

SIP traces attached