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New Member

One Way Audio CCM 4.0(2a)

Intermittently, only on outbound calls, you will see your phone ringout, and even connect, but you (the caller) hear no audio.

On the recipient end, their phone rings and they can hear anything said by the caller.

It's very infrequent, but bothersome.

I suspect that 1 of the 9 PRI's we use may not have a route back to the Call Manager. This is just a guess... I actually have not researched that yet. Was wondering if anyone has experienced anything similar.


Re: One Way Audio CCM 4.0(2a)

You should better open a TAC Case, or:

1- try to Upgrade the Phone firmware

2- Ensure that your Route List/Group are well configured

3- try to sniff the Call (ie Ethereal) while you re experiencing this One Way Problem.

4- Double Click the help button on your phone while having this issue, and see the statistik.

5- go to the EventViewer of the CCM and see if there is some error.

6- is this problem happening just during peak hour?

7- Ensure that your switch is not dropping any packets...etc

Hope this help...

New Member

Re: One Way Audio CCM 4.0(2a)

What IOS version and what Gateway.

I had something very similar and it ended up being the IOS I was running on a 2821.

New Member

Re: One Way Audio CCM 4.0(2a)

Cisco IOS Software, Cat6K-lc Software (wscmm-I6S-M), Version 12.3(8)XY3, RELEASE SOFTWARE (fc3)

cisco WS-SVC-CMM Cat6k Voice Linecard (R7000) processor (revision 0xFF) with 196

608K/65536K bytes of memory.

R7000 CPU at 400MHz, Implementation 39, Rev 3.3, 256KB L2 Cache

Re: One Way Audio CCM 4.0(2a)

Hello Jason,

i think you are on the right track with one of the PRIs not having a rout back to CallManager. 1-way voice is almost always a routing issue. If the PRIs are on different gateways you can try pinging the CM from each gateway. If they are on the same gateway then can you post the config or juts take a deeper look at it?

Hope this helps

Please remember to rate all replies

New Member

Re: One Way Audio CCM 4.0(2a)

I agree, if the PRI's are on different gateways. It's also a good idea to bind the source interface for mgcp or h.323 to use. I had a one-way audio issue that occurred after someone defined a loopback interface, and mgcp decided to use that address as its source address. Unfortunately that address wasn't routable on the rest of the network.

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