PRI debugging instructions

very good tip for PRI debug, credit by jpatel who post it on Sangoma A101 E1 line All circuits are busy

Asterisk PRI Span Debugging

Please follow these steps when faced with dead span:
Record the stdout to file for each command.

1. wanrouter status
Check that wanpipe status is Connected
2. wanpipemon -i w1g1 -c Ta
Check the physical T1/E1 Alarms
3. Run: ifconfig
Make sure that tx/rx counters are incrementing.
4. tail -f -n 100 /var/log/messages
Check for any wanpipe errors in messages
5. wanpipemon -i w1g1 -c trd
Run a dchan trace and check that you are seeing incoming and outgoing traffic.
(Note: this option only works with TDMV_DCHAN option enabled, which should be enabled by default.)
6. From asterisk CLI
run: pri show span 1
Check that spans are UP and Active.
run: pri intense debug span 1
Confirm that in/out messages match the trace messages in step 5: from wanpipemon dchan trace.