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CM 5.1 7937G PSTN Problem - FIXED


I have purchased some 7937G phones for a customer. They are setup on Call Manager 5.1 which is a supported platform, however calls to the PSTN get dropped almost immediately.

They are running the lastest device firmware.

I have checked for any CSS related problems.

I suspect a Codec issue, looking at the stream info on the 7937G web page it looks like it is trying to use G722.

The region specifies G711. I have advertise G722 disabled on CUCM enterprise config.

Does anyone have any experience of the this problem?

Can anyone advise how I can proove this theory, I guess a gateway debug is required or would it be a Call Manager trace?

Thanks in advance!


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New Member

Re: CM 5.1 7937G PSTN Problem - FIXED

Fixed, upgraded my IOS H.323 gateways to 12.4(20)T4, which includes support for G722.

Strange thing is that the call goes through as G711 anyway, but seems G722 support is required in IOS to reject that codec, before it was trying to make the call to the PSTN using G722. I don't fully understand it to be honest, but it is working now.

I hope this helps someone else.

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