I did check the QoS settings. Nothing made any difference.

I was playing with the default gateway on the LIPU and set the ip address to the cisco router's ip address. That seemed to do the trick. We were able to make multiple in/out/voicemail calls with no problems at all with the ip phones.

Not sure why our main gateway wasn't doing the trick. I had a static route in there pointing to the cisco router. In fact when you'd initially put a call thru the ip phone it'd work. Just not after. Yet voicemail worked fine everytime.... as did ip phone <-> ip phone conversations between buildings.

Weird.... I'm satisfied with the fix I guess. I haven't implemented it yet but we'll see how it goes next weekend.

A list of ports used by the phone might be useful in the future if you have one handy.

Thanks again!