Region Configuration

Unanswered Question
Mar 29th, 2008

When a region in CUCM is configured for higher codec (say g711) does it mean that lower codec g729 also works if phone and gateways in the region accept?


I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4.8 (3 ratings)
Jaime Valencia Sat, 03/29/2008 - 14:47

actually it will work, if in the scenario there is a GW involved and you hard-code the dial-peer to G729 you can use the codec.

the region configuration determines what will be the max BW that can be used for voice and anything less than that amount if the endpoints can use the same codec works

from the doc:

The audio codec determines the type of compression and the maximum amount of bandwidth that is used per audio call.

if you're using CUCM 6 and 3rd G phones even if you set the region to use G711 and the phones can use G722 they may use it overriding the region config



if this helps, please rate

mattcalderon Sat, 03/29/2008 - 15:22

I agree with J, but you can only hard code the dial-peer if you have a H323 gateway. This would not apply to MGCP.

I was unaware though about CUCM6 and 3rd G phones over-riding region configurations. What about 4 & 5?

Thanks for the tip


Jaime Valencia Sat, 03/29/2008 - 15:49

I know for a fact that 5.x and 6.x have it, but i would need to double-check the support on 4.x but i think the support started with 5.x

Release Notes for Cisco Unified CallManager Release 5.1(3)

Using the G.722 Codec

When enabled, the service parameter allows Cisco Unified IP Phones (such as 7971, 7970, 7941, 7961) to negotiate and use the G.722 codec when calls are within the same region.

It uses the same BW as G711 but the technology used differs on the fact G722 has a higher sampling rate which carries more info in the same BW as a G711 call, it's explained better in the link in case you want to know some more on this codec

since the codec has a better quality over the same BW as G711, if the phones are capable of using it, they will, even if you have the region to G711. if you have the region configured to a codec that uses less than 56K it won't work and then you will use the codec from the region



if this helps, please rate

mattcalderon Sat, 03/29/2008 - 17:17

Excellent, Excellent information my friend. Thanks for the documentation.



This Discussion