I'm trying to configure SIP on CME for the first time, and I can get phones to register, but not communicate with gateway. I get disconnect cause 38, I suspect I'm missing something from the config. Can you point me in the right direction.
At some time in the future we will be moving to a SIP Provider, but I wanted to get more experience of SIP on CME communicating with both a Gateway and a SIP Server. I want to have IP Phones registered on CME communicating with both if possible.
Especially in case of 7912, is not worth to use phones in SIP mode.
Even if you have SIP provider, SCCP mode works much better.
try to concentrate on:
dial-peer voice 200 voip
Enable 'debug ccsip message' and try an outbound call. The SIP INVITE generated by the IP phone should be correctly routed by the dial peer. If the INVITE goes out from the DP, your CME is correctly working and it's a WAN issue.
add this to your config
voice service voip
bind control source-interface FastEthernet0/0.71
it should be necessary, but I have found it to be