Issue began on incoming calls at first, where after working fine for several days, all incoming calls (on channel one) would fail. Monitoring channel one, it shows as "idle", and the state never changed when a failed inbound call occurred. I set channel one to busy-out thinking it would roll to channel two, but would still attempt only on channel one and then fail. Returned channel one to service, and calls come through again. After approx 24 hours the same issue would re-occur, and busy-out/return on channel one would remedy again (temporarily).
I thought maybe simultaneous incoming and outgoing calls were colliding on channel one and locking it up, so I re-programmed the trunk group in reverse order from 15 to 1 (only 15 channels available on this PRI). All was well for a couple weeks, until calls started failing again, but now both inbound and outbound. When inbound fail, I busy-out/return channel one and they start flowing again. When outbound fail I busy-out/return channel fifteen and they start flowing again. As it was for inbound, the state of channel fifteen always shows "idle" during a failed outbound attempt. Obviously this is not an acceptable permanent solution.
Given the usage at this site, I highly doubt there are fifteen concurrent calls in the same direction, either in or out, that would cause an inbound/outbound simultaneous pair of calls to occur on one of the same failing channels, either one or fifteen.
Any suggestions?
Thanks.
