Transcoding for Software Conferencing not working

Unanswered Question
Aug 10th, 2008

I have a router configured with 3 PVDM-12 DSPs. They are configured for transcoding and conferencing.

show sccp returns the following:

SCCP Admin State: UP

Gateway IP Address:

Switchover Method: IMMEDIATE, Switchback Method: GUARD_TIMER

Switchback Guard Timer: 1200 sec, IP Precedence: 5

Max Supported MTP sessions: 0

User Masked Codec list: None

Transcoding Oper State: ACTIVE - Cause Code: NONE

Active Call Manager:, Port Number: 2000


Conferencing Oper State: ACTIVE - Cause Code: NONE

Active Call Manager:, Port Number: 2000


Call Manager:, Port Number: 2000

Priority: 1, Version: 3.1 or Higher

I have 3 Media resource groups in a single Media resource group list.

1. Xcode resources from above router

2. Software conf resources from Call Manager

3. Conf resources from above router.

Hardware conferening works fine when I move the hardware CFB above the CCM Software CFB in the resource list.

However, when I give Software conferencing higher priority, it does not work, when I try to connect from a region that uses G729. It appears that my transcoding resources are not working properly for some reason, but they are registered with Call Manager and the conferencing resources on the same router function properly. As you can see from the show SCCP all looks good. Transoding and Conferencing are ACTIVE on the router.

If I try to dial a meet me number when Software conferencing has the priority in the MRGL I get a busy signal. With Hardware conferencing as the priority, it works fine. Can't figure out for the life of me why the transcoders don't work.

thanks in advance

I have this problem too.
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Michael Owuor Sun, 08/10/2008 - 11:04

Hi Shaun,

Please verify that the software conference bridge has a MRGL that gives it access to the hardware transcoder resource, which will act as the go between for the endpoint using g.729 and the software conference bridge which only supports g.711.

If you have the configuration described above and still have the problem, please post the CCM trace here from your test call.



sskillin Sun, 08/10/2008 - 12:40

Ah yes. It used to, but something must have changed. Ok, that was it. The device pool that the Software CFB was in, did not have the MRGL assigned.



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