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New Member

Voice only working in one direction

I know this question was asked a few weeks ago but I can't find it.

Here is the config. Call Manager 3.1 3640 with 12.2(11)T PRI running MGCP.

When a user dials out you can hear the user but the called party cannot hear the user.

I remember people talking about a codec mismatch but I'm not sure how that could be since this router is managed by MGCP.

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5 REPLIES
Bronze

Re: Voice only working in one direction

Codec mismatch and blocked RTP streams are both problems with one-way voice. Do you have any codec lines on your router? Has anything changed or is this a new install?

Rick

New Member

Re: Voice only working in one direction

There are no codec lines in the router. This is a new install in which I am trying to have as much done by MGCP as possible

There are no firewalls between the phone and the gateway or the Call Manager.

Bronze

Re: Voice only working in one direction

If you run "debug ip udp" on the 3600, then make a call, do you see UDP traffic going each way between the devices?

Rick

Re: Voice only working in one direction

Is the router being used to do any routing?

If not (and I know this sounds a bit silly ) turn on IP routing. You may find that the default config on the router has not got routing turned on.

Also have you done the H323-gateway bind srcaddr command to bind the h323 to the router interface.

Paul

New Member

Re: Voice only working in one direction

Thanks for the help guys. I figured out the problem. The router was using the loopback interface which was inadvertently turned up. This address was not advertised thus the one way calling problem.

Thanks for the assistance. Sometimes the simplest problems can be such a pain.

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