Called External Party Unable to Hear Caller

[Randy Calderon]

Hello Experts,

In the event that the IP phones fallback to Unified CM 2, and when the user makes an outside call and the called party picks up, the caller cannot be heard on the called party's end.

I am probably missing a configuration somewhere. My initial thought is the H323 gateway. I have a voip dial peer pointing to Unified CM 1 but not to CM 2. If this is indeed the issue, how do I make the H323 gateway aware of the 2nd CUCM server that I have?

Thank you,

Randy C.

[Vivek Batra · Accepted solution]

With the information provided, I'm not sure the exact reason of one way audio however with respect to your question of having information in H.323 gateway about Unified CM 2, you need to have duplicate dial peers pointing to Unified CM 2 with 'preference 1' attached to them. Doing so, when Unified CM 1 goes down, gateway will route the calls to Unified CM 2. 

[Randy Calderon]

Hi Vivek,

Thank you. That's the answer I was looking for when it comes to the dial peers. Do you know of a way I can manually set the IP Phone to use Unified CM 2? This is for testing.

Thank you,

Randy C.

[Vivek Batra · Accepted solution]

Create new call manager group and put only Unified CM 2 here.

Create new Device Pool and assign newly created call manager group here.

Assign newly created Device Pool to desired phone. This phone should now registered to Unified CM 2 only with no redundancy.