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New Member

SRST,G.729/G.711 & Transcoder Issues...Advice Needed

dear folks

am currently abt to deploy a centralised call-processing (with 3640) WAN using SRST at 3 remote sites (with1760V). G.711 will be used @ the central site whilst G.729 @ the remote sites. As such, I was wondering if its possible to opt for a software transcoder option under the CCM (from G.729 to G.711 & vice versa), rather than a hardware based transcoder. Will this be feasible ?

How/Where does the MTP media resource come into effect if the s/w option was chosen ?

Another matter in mind, if I'm not wrong,SRST supports only H.323 currently. What about MGCP ? I had planned to implement using MGCP, but with the recent postings, it appears SRST are geared 2wards H.323.

Would appreciate any advice from folks whom have made successful SRST deployments. Thanks!


New Member

Re: SRST,G.729/G.711 & Transcoder Issues...Advice Needed

Sean, In order to to transcoding you will need hardware DSP's to fulfill this requirement. What I don't full understand is why you need transcoders?

As the Gateways and the IP Phones support both G.729 and G.711, you do not need them. If you have Applications or other products that ONLY support G.711 then you may need them at the central site. Also MTP is normally only required when used with a H.323 device that does not support H.323v2 and the Empty Capabilities Set (ECS). All Cisco GW's support this and do not require an MTP.

Regarding SRST and MGCP :- You require the MGCP fallback feature that allows a MGCP GW to become H.323 when the CallManager is unavailable.

This allows SRST to utilize the gateway. This will be available in 12.2.11T in late July, 02.

The MGCP Fallback feature is in 12.2.2XN however SRST is not. The two IOS trains merge at 12.2.11T

Hope that helps, Graham

New Member

Re: SRST,G.729/G.711 & Transcoder Issues...Advice Needed

What about conferencing resources in a g.729 environment. Don't you still need hardware DSPs to setup as a HW conference bridge if your phones are in a g.729 region?



New Member

Re: SRST,G.729/G.711 & Transcoder Issues...Advice Needed

yes you do. if you region g.711--->g.729 vise versa