Do I need a transcoder for outgoing calls IP Phone ->UCMSIP trunk->CUBE-SIP-> ITSP if I want to use g729 codec all throughout?

[romano_ortega]

Do I need a transcoder for outgoing calls IP Phone ->SIP trunk->CUBE-SIP-> ITSP if I want to use g729 codec from IP Phone to CUBE to ITSP all throughout.

We have tried to set-up the g729 region from IP Phone to SIP Trunk (CUBE) and as per ITSP they are now in the g729  but in the IP Phone when you hit ??, we still see it as g711. Does the MTP point required plays role here because it is tick when we do the testing (as set it up as g711 and g729 preferred orginating codec in the SIP trunk-CUCM) but still no luck in achieving the g729 from IP Phone to CUBE to ITSP without using the transcoder.

[Jaime Valencia]

Yes, if you're using CUCM MTP, it's only G711, you would need to drop the MTP from the call flow, or as you mention, add an XCODER

[romano_ortega]

@ Jamie If I un-tick the MTP point required in SIP trunk will make the call leg from IP Phone to CUBE g729 (w/o hw resource), I have also tried to use g729 preferred originating codec, but still the IP Phone is using g711.

I have seen a documentation states:

" To configure G.729 codecs for use with a SIP trunk, you must use a hardware MTP or transcoder that supports the G.729 codec." - I read this on the CUCM help page under configuring SIP trunk setting.

Our ultimate goal is to use g729 without using HW MTP/ transcoder.

IP Phone ->CUCM SIP Trunk ->CUBE-> ITSP

[Ayodeji Okanlawon]

It is difficult to predict why your calls are using G711 without seeing the traces of the call and your configuration.

If you have selected use MTP and your MTP originating codec is set to G711, then for this to work the region between your phone and the MTP has to be G711 which means that media will be terminated on the MTP using G711 codec.

You can send a debug ccsip messages along with your sh run and we can determine why G711 is been used.

[romano_ortega]

I saw also in the CDR logs that the IP Phone media transport going to CUBE is in G711.And as well in the wireshark capture of the IP communicator that the CUCM invoke to use the g711 codec but as per ITSP logs they are now in the g729.

@ Jamie If I un-tick the MTP point required in SIP trunk will make the call leg from IP Phone to CUBE g729 (w/o hw resource), I have also tried to use g729 preferred originating codec, but still the IP Phone is using g711.

I have seen a documentation states:

" To configure G.729 codecs for use with a SIP trunk, you must use a hardware MTP or transcoder that supports the G.729 codec." - I read this on the CUCM help page under configuring SIP trunk setting.

Our ultimate goal is to use g729 without using HW MTP/ transcoder.

IP Phone ->CUCM SIP Trunk ->CUBE-> ITSP