I have a cisco GW connected to PBX Nortel, whe I make a phone call from the ip phone it travel to the ccm-GW-PBX-ISP.

It always take the channel 31, and then I tray to make a second call and send a busy tone.

Then if in the timeslot I change the 1-31 to 1-30, and i try to make a call it says "the call cannot be possible as you dialed".

Then if in the serial :15 interface i configure de ascendng or descending command, and I try to make a phone call it send me a busy tone.

Any Idea?