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New Member

Force a codec

Can I force an IP phone at a remote site that is behind a pix 501 to use a specific codec like g729 when it talks to my central site phones, yet leave my central site phones to use g711 when they talk amongst themselves?

12 REPLIES
Blue

Re: Force a codec

Brandon,

That is accomplished by defining Regions in Call Manager, and selecting the appropriate region in the device pool.

Please rate helpful posts.

Dave

New Member

Re: Force a codec

can I do regions in Call Manager Express?

Blue

Re: Force a codec

My bad, when you mentioned multiple sites, I assumed Call Manager, not CME.

New Member

Re: Force a codec

Can you do this with CME (any version)?

Hall of Fame Super Gold

Re: Force a codec

CME does not support regions. If you want g729 for a phone, configure that either at ephone or ephone-template level.

New Member

Re: Force a codec

Are there any examples of this that can be viewed?

Hall of Fame Super Gold

Re: Force a codec

ephone xx

codec g729r8

that's it.

New Member

Re: Force a codec

The command at this level does not exist at least for this IOS that I am aware of. c2600-ipvoicek9-mz.124-3f.bin (running cme 3.3) Is there an alternate place for this command or am I just missing something completely?

Gold

Re: Force a codec

when you are doing this with a remote phone which is not registered to this CME, it would use a voip dial-peer (considering this a voip call). voip dial-peers by default use g729 codec and CME Phones by default should use g711 when there is a call between 2 phones registered to the same CME.

With no codec being configured, you should not need any command as this is the default behaviour of CME and voip dial-peers

Hall of Fame Super Gold

Re: Force a codec

You are missing CME 4.0 and 4.1 :)

New Member

Re: Force a codec

I am running CME 3.4 and do not have that option when in config-ephone. Is there a way to force a local, registered phone to use a different codec? These are "local" because they are at the other end of VPNS, but they are on home broadband connections so g711 results in lots of clipping and loss.

Thanks,

Chris

Hall of Fame Super Gold

Re: Force a codec

Hi,

As I mentioned below, g729r8 is an option for CME 4.0 and onwards. Also note, that if the network is lossy, you can have poor results also with g.729, because it's a codec that suffers if there is packet loss. So in any case you should look at optimizing the QoS as much as possible.

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