The system is an SL2100. Digital phones in the office and a single IP phone in the remote office. The remote phone complains that intercom calls from the main office are sometimes one way audio. The remote phone can't hear anything. The main office can hear. The remote phone shows that they have connected. This happens to about 20% of the calls. I haven't heard that any trunk calls are affected.

It's easy to blame it on the internet, or even on the LAN settings. Is there anything I cold do to identify for sure and fix the problem?

Thanks.
Jim

Have you tried checking 15-05-50 Peer to Peer? If its on uncheck that way it always goes back through the system to create the call.

Thanks oobie, I'll give it a try. It was checked.

Yoda,
I do believe it is on by default. I've had some congested networks and Support has had me turn that off and change the codec and always seem to correct the similar issues you are having.