Calls from Cisco 9971 / video phones fail

As video enabled phones become more prevalent on users' networks and audio and video enabled devices continue to converge and ride on the same facilities, I imagine this will become a more common problem, but it's the first time I've bumped into it.

The symptom was a user testing new 9971 video phones found they could dial throughout the Cisco CUCM enterprise, and the video feature was attractive.   They then found that they were unable to call from the 9971 phones to the Avaya PBX phones they were migrating away from.  Other 7900 and 6900 series phones could call the Avaya phones without issue.  The facility between the Cisco CUCM and Avaya PBX was an H.323 gateway supporting a single PRI.

Ultimately the issue was that the ISDN Q.931 SETUP message from Cisco indicated the Transfer Capability was Unrestricted Digital, and the Avay PBX was rejecting the call.

The fix was to add bearer-cap speech to the voice port configuration on the H.323 gateway.

An example of the failed call using debug isdn q31 where Transfer Capability = Unrestricted Digital is the offending message is:

Jul 11 15:14:20.163: ISDN Se0/0/0:23 Q931: Applying typeplan for sw-type 0xD is 0x0 0x0, Calling num 3990
Jul 11 15:14:20.163: ISDN Se0/0/0:23 Q931: Sending SETUP  callref = 0x115D callID = 0x90E9 switch = primary-ni interface = User
Jul 11 15:14:20.163: ISDN Se0/0/0:23 Q931: TX - > SETUP pd = 8  callref = 0x115D
Bearer Capability i = 0x8890
Standard = CCITT
Transfer Capability = Unrestricted Digital
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0xA98387
Exclusive, Channel 7
Calling Party Number i = 0x0081, '3990'
Plan:Unknown, Type:Unknown
Called Party Number i = 0x80, '7121'
Plan:Unknown, Type:Unknown
Jul 11 15:14:20.191: ISDN Se0/0/0:23 Q931: RX < - CALL_PROC pd = 8  callref = 0x915D
Channel ID i = 0xA98387
Exclusive, Channel 7
Jul 11 15:14:20.195: ISDN Se0/0/0:23 Q931: RX < - DISCONNECT pd = 8  callref = 0x915D
Cause i = 0x81D8 - Incompatible destination
Jul 11 15:14:20.195: ISDN Se0/0/0:23 Q931: TX - > RELEASE pd = 8  callref = 0x115D
Jul 11 15:14:20.227: ISDN Se0/0/0:23 Q931: RX < - RELEASE_COMP pd = 8  callref = 0x915D

An example of a successful call at the same site over the same circuit with a Transfer Capability = Speech is here:

Jul 11 15:13:02.743: ISDN Se0/0/0:23 Q931: Applying typeplan for sw-type 0xD is 0x0 0x0, Calling num 7510
Jul 11 15:13:02.743: ISDN Se0/0/0:23 Q931: Sending SETUP  callref = 0x1157 callID = 0x90E3 switch = primary-ni interface = User 
Jul 11 15:13:02.743: ISDN Se0/0/0:23 Q931: TX -> SETUP pd = 8  callref = 0x1157 
Bearer Capability i = 0x8090A2 
Standard = CCITT 
Transfer Capability = Speech  
Transfer Mode = Circuit 
Transfer Rate = 64 kbit/s 
Channel ID i = 0xA98382 
Exclusive, Channel 2 
Calling Party Number i = 0x0081, '7510' 
Plan:Unknown, Type:Unknown 
Called Party Number i = 0x80, '3427' 
Plan:Unknown, Type:Unknown
Jul 11 15:13:02.767: ISDN Se0/0/0:23 Q931: RX < - CALL_PROC pd = 8  callref = 0x9157
Channel ID i = 0xA98382 
Exclusive, Channel 2
Jul 11 15:13:02.775: ISDN Se0/0/0:23 Q931: RX < - ALERTING pd = 8  callref = 0x9157
Progress Ind i = 0x8188 - In-band info or appropriate now available 
Jul 11 15:13:10.475: ISDN Se0/0/0:23 Q931: RX < - CONNECT pd = 8  callref = 0x9157
Progress Ind i = 0x8182 - Destination address is non-ISDN  
Connected Number i = 0xA1, '3427' 
Locking Shift to Codeset 6 
Codeset 6 IE 0x28  i = 'LAB FAX'
Jul 11 15:13:10.475: %ISDN-6-CONNECT: Interface Serial0/0/0:1 is now connected to 3427 N/A

The change in the configuration to correct the issue was:

2901-VGW(config)#
2901-VGW(config)#voice-port 0/0/0:23
2901-VGW(config-voiceport)#bearer-cap ?
  3100hz   enable 3100hz
  speech   enable speech
2901-VGW(config-voiceport)#bearer-cap speech
2901-VGW(config-voiceport)#

No configuration change in Cisco CUCM was necessary and the voice-port did not need to be reset.

Further information and detail can be found here:
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a0080569b65.shtml