CUCM : Conference bridge and Transcoding

[Nikolay Kozyrev]

Hello, gentelment's.

I have 2 CUCM cluster connected via h323 trunk non gatekeeper controlled. Some conf calls are working , sometimes not.

Please explain me when CUCM are using a conference bridge and when a transcoder for the conference calls ? What is the difference ?

I'm a little bit confusion.

Thanks in advance.

[Chris Deren]

Conference bridge is only used when a conference is initiated by pressing the conference button, pretty trivial. depending on the configuration of the conference bridge such as what codecs are defined in the DSP profile (assuming HW bridge here) a transcoder may need to be requested if the conference bridge does not include a codec required for any of the participants. Transcoder simply transcodes between different codecs that cannot be negotiated natively.  If you are using software conference bridge those only support G711 codec so if remote conference participant is configured to use G729 a transcoder will be needed.

HTH,

Chris

[Nikolay Kozyrev]

Hello, Chris.

Thank you for detail reply. In that way if I have had a hardware conference bridge it may converts codecs by itself and NO transcoder needed . Am i right ?

[Chris Deren]

Correct, simply define all the codecs you need under the dsp profile configuration.

HTH, please rate all useful posts!

Chris

[Nikolay Kozyrev]

Many, many thanks )) Chris.

[Chris Deren]

Glad to help. Please rate all useful posts!

Chris

[Nikolay Kozyrev]

One more thing Chris if you do not mind.

at the same situation when 1111 phone  ( CUCM 1) dial to the 2222 phone (CUCM2) via the same h323 trunk and pres hold button. No hold - silense. ext 2222 does not heared nothing . but when i checked ant the truck at CUCM2 option MEDIA TERMINATION POIN REQUIRED all is worked fine. what is the problem?

[Chris Deren]

Are you using Multicast MOH? Perhaps mulicast IP address cannot be routed.

Chris

[marmugam]

I undersantd you far end receives Silence. But when you resume the call does the call gets connected again or it disconnects ? Trying to understand if it  only MOH issue or suppementary services issue without MTP. If it is only MOH issue, then try using Unicast MOH to see if you can hear MOH.  If that fails, then we may need to look into the configuration of the ICT Trunk or DP of ICT trunk  to see if does have Correct MRGL/MRG with MOH server.

[Nikolay Kozyrev]

hello, gentelmens.

I will try to check it morrow when will be in office and let you know

Thanks for you ideas and help.