Hello-

I have an NBX V3000 running R5 code. All phones are 3102 business sets. I have three phones that are located offsite, with a full T1 between here and the site. There are Cisco routers on either end of the T1. The system is using IP-on-the-fly, but these three remote phones are using static IP's.

The problem I'm having is that these three phones get no audio when they call amongst each other. Calls do seem to go through, and the called station rings, but neither party can hear the other. All calls to and from anywhere else work fine. (Including the 35 or so IP phones at the main location.)

One thing I have tried is to enable the medium compression on these phones. This did not help, so I changed it back because it did affect voice quality. I also enabled multicast on my routers to get the correct time on the phones, as well as making the park lights work. This did fix those two problems but had no effect on the audio problem.

Anyone have any suggestions?

Oldyeller