Configure and Test Transcoders

Unanswered Question
Dec 6th, 2007

We have a 2811 with (2) PVDM2-64 modules on board. I want to know the best way to configure this for conferencing and transcoding and also verify the dsp's are being used. I was able to test a conference call and see the dsp resources in use, but when I do a site to site call (configured to use G711 - G729 between sites) I don't see any DSP's in use. I have verified the phone I am using and all other phones are correctly configured and using the right Media Resource group & list.

Any thoughts?

sccp local FastEthernet0/0

sccp ccm 10.x.x.0 identifier 2 version 4.0

sccp ccm 10.x.x.1 identifier 1 version 4.0



sccp ccm group 1

associate ccm 1 priority 1

associate ccm 2 priority 2

associate profile 1 register CONF

associate profile 2 register TRANS


dspfarm profile 2 transcode

description TRANS

codec g711ulaw

codec g711alaw

codec g729ar8

codec g729abr8

maximum sessions 29

associate application SCCP


dspfarm profile 1 conference

description CONF

codec g711ulaw

codec g711alaw

codec g729ar8

codec g729abr8

codec g729r8

codec g729br8

maximum sessions 6

associate application SCCP

The results of this command were during a conf call and several site to site calls:

sh dspfarm dsp active


0 6 1.1.115 UP 1 USED conf 2 6059 65640 65640

0 6 1.1.115 UP 1 USED conf 2 6062 65483 65456

0 6 1.1.115 UP 1 USED conf 2 6068 59739 59719

Total number of DSPFARM DSP channel(s) 1

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There are two types of Digital Signal Processors (DSPs) that can register with Cisco CallManager C549 or C5510. The type of DSPs determine how the DSP resource registers with Cisco CallManager. C5510s register to Cisco CallManager as Cisco IOS Enhanced (Conference Bridge or Transcoder), while the C549s register as Cisco IOS (Conference Bridge or Transcoder) type

You can refer this guide for more information

MARTIN STREULE Thu, 12/13/2007 - 13:40

I don't know what you configured on the CUCM, but my guess is that you don't transcode at all.

Check the used codec on the phones ("doubleclick" on the "?" button on the phone). I one using G711 and the other one G729 or both G729?

BTW: There is another command to check transcoding/conferencing; sh sccp connection


CHRIS KALETH Thu, 12/13/2007 - 13:44

Both are g729. I am just wanting to verify the transcoding resources are being used. If I recall does the Call Manager provide any DSP resources (by default). If so, I checked our CM config and the phones don't have the CM as part of the Media Resource list.


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