Has anyone experienced a problem with VoIP where, after placing a call on the VoIP, the party on the other end can't hear you? So far I've only experienced this with internal calls and the calls are always going between VoIP and TDM. We're running an Option 61C with Succession 3.0 and a Media Gateway Card for the VoIP-to-TDM translation.
Direct access your Media Gateway ports and make test calls from a proprietary phone to an IP phone. We had this happen on a site recently. What I'm told is that the whole Media Gateway Card usually goes out, not just one port, so it shouldn't take long to find the bad one and disable it. BTW, our switch was (an 81c) was also running Succession 3.0. The Media Gateway Card that was bad disabled about five of it own ports. So you might just start by STATing the Media Gateway Loops first.
BTW, if it is a bad Media Gateway Card, and you have standard TDM trunks, you should also be having intermittent problems dialing external numbers from an IP phone. (How intermittent depends on how many Media Gateway Cards you have.)
Thanks for the great response. We only have one MGC and this seems to describe our problem perfectly (the frequency of the issue, etc). I was thinking yesterday that the issue was probably with the MGC. I have our sevice vendor coming out today and this is the first thing we'll check.