Okay, now I am really confused...

On two CME's I have conferencing setup as software (or so I believe):

telephony-service

max-conferences 8 gain 6

I have DSPs setup for transcoding only (not conferencing ... 28xx so PVDM2's on motherboard):

voice-card 0

dsp services dspfarm

sccp local GigabitEthernet0/0.120

sccp ccm 10.1.120.10 identifier 11 version 7.0

sccp

!

sccp ccm group 1

description Transcoding DSP Resources

bind interface GigabitEthernet0/0.120

associate ccm 11 priority 1

associate profile 1 register mtp00241432fc80

!

dspfarm profile 1 transcode

description Transcoding DSP Profile

codec g711ulaw

codec g711alaw

codec g729ar8

codec g729abr8

codec g729r8

maximum sessions 5

associate application SCCP

!

telephony-service

sdspfarm units 5

sdspfarm tag 1 mtp00241432fc80

If I place a call from the remote site to the local site (going over a dial-peer with the default g729r8 codec) and try to "confrn" I get a "cannot complete conference" message.

But if I change the dial-peer to "codec g711ulaw" and try the same thing, it works fine.

So from my point of view, I am not using any DSP resources for conferencing. I believe based on the CME System Admin Guide (01-20-2009) on pg 694 "Conferencing Overview" ...

"Conferencing allows you to join three or more parties in a telephone conversation. Two types of

conferencing are available in Cisco Unified CME: ad hoc and meet-me.

Ad hoc conferences are created when one party calls another party, then either party adds one or more

parties to the conference call. Ad hoc conferences can be hardware-based or software-based, depending

on the number of parties. Hardware-based ad hoc conferencing uses digital signal processors (DSPs) to

allow more parties than software-based ad hoc conferencing, which allows three parties only."

Your email implies I have to use hardware based no matter what. Can't I use software ad-hoc at 3 parties max without using DSPs?

Yes, you can do software for 3 G711 parties.

If you want to do any G729 conferencing it will require hardware.

The only question is if the transcoder will convert G729 to G711 for a software conference. I would have to play with this in the lab, but it looks like you already have this configured.

Looking at the configuration guide, it looks like this is relevant:

http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmetrnsc.html#wp1010393

The codec g729r8 dspfarm-assist seems in order here.

-nick

This is a production system and I don't want to "play" ... where do you think that goes .... on the dial-peer between buildings or the transcoding resource or ???

Hi CJ,

No playing required on your part - I just haven't tried this particular feature out before.

Add this to your transcoding profile:

dsp profile x transcoding

g729r8 dspfarm-assist

What this command does is assist the software conferencing with transcoding for this specific situation. If you had hardware conferencing configured also, it would not make any sense to use a transcoder to send it to a hardware conference.

So, what this command says that if a conferencing session needs assistance - lend it. The transcoder by default just doesn't have the context to know whether it should or not, so you need the codec "g729r8 dspfarm-assist" configured under the dspfarm profile.

hth,

nick

hi,

this is a document that helps me to configure ad-hoc conferencing in cme.

i hope it helps

Hi Manuel,

Please where did you find this CME tech tips ? do you have others regarding CME ?

Best Regards

Olivier

Hi Olivier,

You can find this and many more on Cisco Learning Network web site:

https://cisco.hosted.jivesoftware.com/index.jspa?ciscoHome=true

Please rate if it helps!

Best regards,

- Adrián.

Hi Olivier,

I found this document in the following link:

http://www.uc500.com/configuring-meetme-conferencig-uc500

Manuel