I am trying to figure out the call fail problem between my cisco 5400 and ISDN/PBX.
Follow the instruction from the manual,enable the DEBUG ISDN Q931, on the cisco 5400. It just shows me ‘debug isdn q931 is on’, but I didn’t see the debug info. Do I need to run another command to see the debug info.(There are active calls and new calls attempt to 5400).
If you are using TELNET/SSH to access the cisco, then you need command “terminal monitor” to enable debug message for this session. Then you need “debug isdn q931 asn1” to enable user-friendly isdn call debug.
Using ‘DEBUG ISDN Q931’ shows normal call clearing,but the what happened is the call duation is very short, say less than 30 sec. Call just got connected and then disconnected right away. Does anyone have good suggestions what cause this problem? I am thinking might be some higher level protocols disconnect the session, and send message to isdn layer, which perform disconnection. No idea where to start checking