CUBE & Codec negotiations...

[Gordon Ross]

In my CUBE, I have two inbound dial-peers from third party services, and an outbound dial-peer to CUCM:

voice class codec 1
 codec preference 1 g711alaw

!

voice class codec 2
 codec preference 1 g722-64
 codec preference 2 g729r8
 codec preference 3 g711alaw

...

dial-peer voice 1 voip

  description Inbound DP-1

  ...

  !Note, no codec preferences listed

dial-peer voice 2 voip

  description Inbound DP-2

  voice-class codec 1

  ...

dial-peer voice 3 voip

  description Outbound DP to CUCM

  !Note, no codec preferences listed

...

The theory is, is that dial-peer 2 will only access G.711 codec, dial-peer 1 will accept anything, and CUBE will send anything to CUCM.

In reality, dial-peer 1 doesn't work. It fails due to codec mismatch. But if I add "voice-class codec 2" to the CUCM outbound dial-peer, then both dial-peer 1 & 2 work.

Why? Why does setting the codec preference on the outbound dial-peer allow the inbound dial-peer to match?

Gordon.

[Brandon Buffin]

Default codec for a voip dial peer is g.729. What is the CUCM configuration? Does it alllow g.729? If not, this would explain dial peer 1 not working. As for adding the voice-class codec command, both dial peers work? I understand dial peer 2 working at this point because inbound/outbound match on g.711.

Brandon

[Ayodeji Okanlawon]

The picture is not complete so any suggestions here are based on assumptions. 

First of all.. Cube will not accept any call on a matched dial peer if the codecs offered do not match what is configured on that dial peer, because technically it can't negotiate those capabilities. 

So in this case if your ITSP sends g711u and g729,then cube will reject the call immediately. So for CUBE to accept a call the codec offered must match one in the dial peer