No audio between 2 CUCMs

[HamzaD]

Hi,

I have two CUCMs (8.5 and 11.5) with phones registered on both via SIP protocol.

Everything was working fine between the two systems till I get complaints saying that: they can't hear or to be heard when calling from phones registered from the first CUCM (8.5) to the secend one 11.5 (NO PROBLEM WITH THE OTHER SIDE) everything works fine from CUCM 11.5 to 8.5 !

Any suggestions or advices would be mush appreciated.

Thanks,

Hamza.

[Dennis Mink]

So  phone on cluster a rings phone on cluster b. Called phone picks up and after that dead air?

Has this worked previously? If you have signalling but no audio then its most likely caused by routing. So verifyif you can ping between phones.

[HamzaD]

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@Dennis Mink wrote:

So  phone on cluster a rings phone on cluster b. Called phone picks up and after that dead air?

Has this worked previously? If you have signalling but no audio then its most likely caused by routing. So verifyif you can ping between phones.

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Thank you for your reply Dennis,

It is exactly as you described, but from phones on cluster B when I call a phone on cluster A everything works fine (the problem is just in one direction from A to B only).

YES! It worked perviously.

I have the two phones in two diffrent Voice VLANs I will check routing between them and tell you.

[Jaime Valencia]

Ideally, routing from A <-> B should follow the same path in your network, but I've seen plenty of times that it doesn't happen and you end up with different routes (and you might see delay in one path, or no routing), you might have not changed anything, but your network team might.

Determine what is your RTP flow, if there are MTP/TRP in the path, and then discuss with your network team.

[HARIS_HUSSAIN]

We can verify if The Two Phone is sending and Receiving the packets to confirm if it is related to routing.
Just enable the Phone Web Page and verify if Send/Received Packets are incrementing when the issue is faced.
More details can be found below

https://community.cisco.com/t5/collaboration-voice-and-video/how-to-troubleshoot-one-way-no-audio-issues/ta-p/3164442

*** Please rate helpful post; Mark "Accept as a Solution" if applicable

Thanks,
Haris

[HamzaD]

Thank you all for your replies,

I noticed that this issue is not always happening (its intermittent) today it works normally (I didn't do any changes) !!

@HARIS_HUSSAIN I will try to see if the packets are incrementing when I get the issue again and tell you the result.