conference participants cucm

Unanswered Question
Apr 28th, 2010
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There is a setup of cucm 4.3. Users in Head Office can initiate a conference with upto 4 participants and more. But when a branch office user initiates a conference

only 3 participants can come to conference, as soon as the the fourth participant is added to conference the phone displays "KEY IS NOT ACTIVE"

Any suggestions to resolve the issue at branch office. The users at branch office are using the conference bridge of subscriber.

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stowellp Fri, 04/30/2010 - 04:52
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Are you using G.729 from the HQ to branch offices?

Have you got hardware conference bridges configured?

The reason why I ask is that the software conference bridge on CUCM can only support G.711.



allan.thomas Fri, 04/30/2010 - 12:52
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As already mentioned the region and codec capabilities are an important consideration within a centralised deployment.  You mentioned that you are using the software conference bridge of the subscriber, therefore you are either using G.711 directly between regions or you are reliant on hardware transcoding sessions in order to negoiate the three way conference from G729 to G711?

Therefore there are two possibilities either you have insufficient transcoding or alternatively you have insufficient location bandwidth between head-office and the remote-office.  Please can you confirm the following:-

  • Region codec between your remote-office and head-office. G.711 or G.729?
  • Location bandwidth between your remote-office and head-office?
  • If you use different codec between sites, how many hardware transcoding sessions do you have?



Hope this helps, pls rate helpful posts.

SJ SJ Thu, 05/06/2010 - 22:01
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Region codec between the site is G.729

Bandwidth is 5 Mbps

I have no hardware transcoder on that site.


allan.thomas Fri, 05/07/2010 - 00:20
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Transcoding will be required specifically at your central site and not your remote office as the codec across your WAN is G.729 and the CallManager CFB is G.711.




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