Setting up Conference Calling - CUCM 6.1

Unanswered Question
May 13th, 2008

I am looking for assistance or pointed in the right direction of setting up conference calling in CUCM 6.1, with 2811 running in SRST mode.

I have a remote site registering to 6.1, with a local ISR running in SRST mode. I do not want to set up a media resource unless I need to.

Here is what is happening.

I call outside line to remote location.

Call is answered.

Called party presses Confr softkey, places call.

New Called party answers, confrn softkey pressed again, call is dropped and I hear fastbusy, however the call between the two stays up.

It sounds like a Codec issue but not sure what to look at.

I have this problem too.
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e.huntley Tue, 05/13/2008 - 11:42

Probably Codec. If you are using the CCM for Conferencing, you have to be talking G.711 to your Media Resources. If you are G.729 you need a Transcoder and the central site.

Rick Morris Tue, 05/13/2008 - 11:53

As of right now no media resource group has been built.

Is this something that can be a default setting? We need to make sure that this can be used at 75 sites that connect into the CUCM. We have built different regions and locations, device pools, etc... to keep them separate in their build but together in the same cluster.

If I go into the Conference Bridge Media Resource group I have CFB_2 and CFB_3

they are in the default device pool. do I need to put these in something else? Or is there something else I need to build?

Codec within regions is G711 and between regions is 729, and on the router is the transcoder config, prefer 711 if call cannot terminate 711 then use 729.

Rick Morris Tue, 05/13/2008 - 12:35

I believe I know the issue:

RET902R001#sh dspfarm dsp all


0 2 9.4.4 UP N/A FREE xcode 1 - - -

0 3 9.4.4 UP N/A FREE xcode 1 - - -

0 3 9.4.4 UP N/A FREE xcode 1 - - -

0 3 9.4.4 UP N/A FREE xcode 1 - - -

Total number of DSPFARM DSP channel(s) 4

and all 4 DSP's are being used for transcoding:

RET902R001#sh dspfarm all

Dspfarm Profile Configuration

Profile ID = 10, Service = TRANSCODING, Resource ID = 1

Profile Description :

Profile Admin State : UP

Profile Operation State : ACTIVE

Application : SCCP Status : ASSOCIATED

Resource Provider : FLEX_DSPRM Status : UP

Number of Resource Configured : 4

Number of Resource Available : 4

Codec Configuration

Codec : g711ulaw, Maximum Packetization Period : 30

Codec : g711alaw, Maximum Packetization Period : 30

Codec : g729ar8, Maximum Packetization Period : 60

Codec : g729abr8, Maximum Packetization Period : 60

Codec : g729r8, Maximum Packetization Period : 60

Codec : g729br8, Maximum Packetization Period : 60

Dspfarm Profile Configuration

Appears I need more DSP's, is this correct? or is there another way to set this up?

Jaime Valencia Tue, 05/13/2008 - 12:47

you need a WHOLE DSP for conferencing, you cannot use any channel for other usage.

if you're already using all the DSPs you do need to add more resources, even if you're using only 1 channel that is not the whole DSP and won't let you configure it for CFB



if this helps, please rate

Rick Morris Wed, 05/14/2008 - 11:03

is there a guide to configure this on CUCM 6.1 as a media resource, and have it set up for each site not just a global setting?

I will need to set this up in different regions, is this possible?

Anyone have links where I can read about the set-up?


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