We have been operating a H323 connection between CUCME and an Avaya PBX for several weeks but have experienced strange behaviour. Initially things seemed fine until users reported calls cutting off. Looking at captures, CME can be seen to send a 'release complete' but we're not able to see what instigates this release. All active calls across the trunk drop together, regardless of the duration of any of the calls.
The other issue is call setup. Calls from PSTN into Avaya and across trunk to CME ip phone work OK but calls originating on Avaya handset following same route fail to connect, apparently caused by Q931 message from CME, cause 65 'Bearer capability not supported'. Captures of both successful and failed calls show identical bearer capabilities from the Avaya (in H225 Setup OpenlogicalChannel), the only difference in the calls, besides originating number, is Progress Indicator - failed calls show 'Private Network serving the local user (LPN), Origination address is non-ISDN' and successful calls show 'Private network serving the remote user (RPN), Call is not end-to-end ISDN - progress information available in-band'.
Has anyone experienced similar problems? Any suggestions where to look next?