I am running Asterisk 1.6 on Ubuntu server 10.04 There is an Audiocodes Mediant 1000 MSBG which acts as an SBC to support remote users on my Asterisk box.
When I make call from internal through the SBC to the remote user, the call works just fine. However when remote users make calls through the SBC to internal users, the internal phones ring, the user answers, and they hear dead air while the remote user continues to hear ringback.
I have isolated this issue to the final SIP 200 OK, in the call setup, sent from the Asterisk box to the SBC. The SBC is basically rejecting the 200 OK because of an inconsistency in the Content-length recorded in the message and the computation performed on the SBC. You can the error in my syslogs, on the SBC, below.
10:08:33.593 : 10.10.1.199 : WARNING : ( sip_stack)(27394 ) !! [ERROR] AcSIPParser: Parse Error. Content length header 296 is inconsistent with the actual body's length 328
10:08:33.593 : 10.10.1.199 : WARNING : ( sip_stack)(27395 ) !! [ERROR] Message type: 200 OK
10:08:33.609 : 10.10.1.199 : WARNING : ( sip_stack)(27396 ) !! [ERROR] Source header:
10:08:33.609 : 10.10.1.199 : WARNING : ( sip_stack)(27397 ) !! [ERROR] Line: 14. Column: 1
10:08:33.609 : 10.10.1.199 : WARNING : SIP/2.0 200 OK
I have found a recorded asterisk issue which seems to be related but I am unsure of how to apply the fix to my system. See link below…
Any help that you could provide would be greatly appreciated.
Thanks in advance.