POTS CALL: Channel not available or channel unavailable, cause value = 3 and disconnect code = 0 if you are trying to make a call over the pots/pstn and the incoming pots call says the above....

Make sure if it's a lab setup that the "isdn protocol emulate-network" is configured under the serial interfaces x/x/x:23 or x/x/x:15, also do make sure the number of pri-group timeslots on the pstn router and the corresponding branch router match... once all rectified shutdown the controller and bring it back up..... you'll see the above "channel unavailable error" in the "debug isdn q931 output"even if the isdn status shows "Multiple Frame Established"... ..