7985 problems with audio only calls

Unanswered Question
Dec 13th, 2008
User Badges:
  • Gold, 750 points or more


I have deployed a CallManager 6.1 cluster with several H.323 gateways for access to the PSTN.

Inbound and otbound calls work ok with standard phones (7965, 7941 and 7911) however I am having problems with outbound calls from 7985 video enabled phones.

When I make a call to a PSTN device it is routed to a H.323 gateway according to the dial plan. However it seems that the 7985 is trying to make a video call via the gateway and this fails. Below is the output of debug isdn q931 on the gateway.

Bearer Capability i = 0x8890

Standard = CCITT

Transfer Capability = Unrestricted Digital

Transfer Mode = Circuit

Transfer Rate = 64 kbit/s

Channel ID i = 0xA9839F

Exclusive, Channel 31

Calling Party Number i = 0x00C3, N/A

Plan:Unknown, Type:Unknown

Called Party Number i = 0x80, '0124224XXXX'

Plan:Unknown, Type:Unknown

The H.323 gateways cannot support video calls so I need some way of forcing the call from the 7985 to be audio only.

Does anyone know how to do this?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (2 ratings)
James Hawkins Sat, 12/13/2008 - 07:57
User Badges:
  • Gold, 750 points or more

Just found the answer on NetPro - I should search more thoroughly before posting.

The answer was contained in the response below from Kenneth Mohammed (Thanks 5 points)

Posted by: kenneth.mohammed - systems technician, AT&T Communication Systems Southeast - May 7, 2008, 9:15am PST

7985 sets try to initiate H.264 video calls by default on all calls. Under your voice-port configuration, you need to have the following:

voice-port x/x/x:23

bearer-cap speech

This should allow your 7985 to make calls to the PSTN.

Hope that helped, and if so, please rate post.


This Discussion