I have a 2801 with a PRI card in it that is connected to a Telerad PBX. There are 12 voice channels setup and about 20 phones hanging off of the PBX.
The problem is that occasionally you hear the echo of your own voice for about 2-3 seconds then everything is fine. Then a minute or so later it will happen again.
There does not seem to be any pattern to it, and there can no other calls up or a bunch.
The echo happens only on the PBX side, not on the PSTN side.
Any ideas where I should start looking?