No audio MGCP

Unanswered Question
Jun 12th, 2008

I would appreciate it if anyone could help me in this issue...

I have been facing a problem when I'm using

IP-phone outside central office, I have no audio.

There are one IP-PBX Panasonic KX-TDE200 behind a Cisco 2800 router at the Central Office.

At the branch office the IP-Phone connect in ADSL router, no firewall.

The IP-phone are MGCP-based.

I have capture the packets during the call. The IP addres at the SDP of MGCP packet are the private IP of Central Office(Eg.: and not the public address (Eg.:

The RTP packets are send to wrong IP address.

I have read about ip inspect name mgcp command, to inspect the MGCP packets.

I want to know if there are any "feature" in cisco 2800 router that could solve this problem?


I have this problem too.
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irisrios Wed, 06/18/2008 - 07:28

If it is IOS MoH from flash then the RTP packets are definitely not going to care about any mgcp/h323 bind command. They just use the IP address on the outbound interface as the source IP address.

Verify that you have selected correct MOH codec in service parameters for Cisco IP Voice Media Streaming Applications. Also, verify that the MTP checkbox is unchecked. If it is unchecked, then check the MTP checkbox in the Gateway settings on the Cisco CallManager.


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