We have captured syslog. The 180 ringing packet is received and reported to syslog. Then debug outputs TP parse error:6 and we don't get ring back on the calling phone, and no audio because the call doesn't complete setup, then we hang up the call. Nothing else comes from debug.
Best we can put together at this point is that it has something to do with the FROM field in the SDP message. When caller ID is set on the 4 digit user account on the PBX (the account the ATA uses to register), the FROM field is populated on outbound PSTN calls with the 10 digit caller ID number (also set only on the server) and whatever name value is assigned to the extension on the server. When we have a combination of name and 10 digit number that exceeds 17 characters (again, all server based settings), we receive the parse error from the ATA debug.
My guess is something in the code of the ATA, but without a document on the error codes or any one having prior experience like this, then we've probably just hit a limitation. We are using an open sourced PBX system so it isn't surprising some inter-op issues exist.
