Codec on SIP trunk calls

[Frenchy1986]

Hi All

Does the codec on a Mitel 3300 automatically change depending on the quality of the call? Ideally I would like it to run in G729 all the time but can't find where to alter this. Any ideas?

If in doubt......Wing it!!

 

[nytalkin]

I have had luck by enabling "Enforce Symetrical Codec" on the SIP peer profile.

NO GOOD DEED GOES UNPUNISHED!

 

[IrwinMFletcher]

Codec negotiation is all about zones. Nothing in the system will trigger a renegotiation based on audio quality.

 

[skinnypuppy56]

in my discussions on this topic it comes from carrier adnd stays compressed in the mitel but very important that voice carrier has it at G729

 

[Supernova99]

The 3300 will always try to negotiate at the codec it is given in the initial call setup.

If the device or route has been setup in a zone that is compressed (G729) it will stay compressed, if not it will always default to G711.

So you could have a situation like this
Calling device supports G729, trunk supports G729 however the called deice does not, in this scenario the call will default to G711.

Or you could have a device which supports G729 as does the trunk and the called device but the device is not in a compression zone.

Or all of the above but no compression licences on the controller.

It takes time and planning to make sure that G729 is applied.

One scenario that I get regularly is calls forwared to Nupoint voicemail. Nupoint does not support compression so in this situation I have had to route calls over a back to back DPNSS link so that the E2T card is the answering point and thus maintains the compression.

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[drsmith45]

Hello Everyone, we have a Mitel 3300 MCD 4.0 connected to a Cisco Call manager using SIP trunks everything works good except when you dial a Cisco extension that routes the Unity voice mail system
the call gets rejected because of the G729 codec used by the 3300
in the Sip profile I have enabled the option Renegotiate SDP to enforce symmetric code
I can not see how on the Mitel side we are using compression G729?
or how to change it so we are locked down to use G711
There is a interop from Mitel and Cisco of course it was written when the 3300 was 7.0 and the Call Manager was 6
any Ideas are appreciated !

 

[IrwinMFletcher]

Those attachments don't open for me....anyone else able to open them?

Do you have a SIP trace?

 

[Supernova99]

There is a newer version with release 9.0 here

http://www.mediafire.com/?0k9d8exiahatk

Share what you know - Learn what you don't

 

[drsmith45]

My apologies I did not mean to start a new thread in Frenchy1986's post
started a new one