uc540 voice compression

[datak2011]

is there some kind of voice compression on the uc540?

A type of voice compression that would require less bandwidth when talking over vpn tunnel or over internet to sip ?

[danplacek]

Yes, use the G.729 codec instead of G.711.

That will save quite a bit of bandwidth.

See: http://www.cisco.com/en/US/tech/tk652/tk698/technologies_tech_note09186a0080094ae2.shtml#topic1

[datak2011]

ok thanks! where can I change this ?

you're really helpful today thanks

[danplacek]

No problem!

If you are trying to set it for a SIP trunk and using CCA, there is an option for this in the SIP trunk config.

To do the same in commandline:

voice class codec 1
 codec preference 1 g711ulaw

change to:

voice class codec 1
 codec preference 1 g729r8

Alternatively, "dial-peers" can be forced to a codec individually:

dial-peer voice 2000 voip
 codec g729r8

I think per your topology though, you have some remote phones that are registered directly to the UC500?

If that is the case, you want to set the codec per phone.

In CCA there is a "preferred codec" dropdown on each phone config screen.

In CLI: (For each phone you want changed)

ephone <#>
 codec g729r8