Gateway Bearer Capability

Unanswered Question
Oct 1st, 2008

I had used the workaround available in 4.2 version of callmanager to change the bearer capability from speech to 3.1khz for fax tramnsmission over ISDN/GSM.

The workaround is to add the following text in the description of the gateway.


Unfortunly this hack seems not working in version 6.X.

Does it exists an other way to change the bearer capability of a call ?

I have this problem too.
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wdrootz Wed, 10/08/2008 - 08:17

You may try using the bearer-cap command in voice-port configuration mode to set the gateway for speech or 3100 hz audio as appropriate

MARTIN STREULE Thu, 10/09/2008 - 01:37

Maybe the "isdn reject vod" command helps you solving the issue. (Interface command)


philippe.blasut... Thu, 10/09/2008 - 23:00

No, I need this functionality in outbound to be able to send faxes over GSM network. The GSM gateway need a 3.1kzh bearer and is rehjecting the speech bearer. I tested it on callmanager version 6.1 and this workaroung is no more possible.

MARTIN STREULE Thu, 10/09/2008 - 23:29

Maybe the "bearer-cap" command mentioned in the other post helps you.

But if this comes directly from the CUCM you're pretty lost.

- open PDI case (maybe they know another workaround)

- open TAC SR

- consider alternatives... H323, additional port for this function.

I did not know the workaround you mentioned. Always interesting. It's a pity that they disappear without a follow-up solution.

Good luck,


philippe.blasut... Thu, 10/09/2008 - 23:53

It could be for an H323 gateway, but I would like to use it for an uplink to a VOIP carrier throught a SBC. And it does not solve the call by call choice of bearer.

Thank you for your suggestions.


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