Multiple channels open on PRI for 1 call

Unanswered Question
Dec 17th, 2008
User Badges:

Once in a while i receive a threshold alarm (>15 channels being used on our QSIG PRI trunk). I then view call detailed history for the trunk on CDR Analysis and Reporting Tool and notice multiple channels being opened by a specific calling number to called number. As an example, during a 2 second period there up to 10 channels that are opened by the same source/destanation call. The origination and destination leg IDs are different for each call so I know that CUCM is involved with setting up each call.

Did anyone experience this before? It happens maybe once or twice a day, quick spike on channel utilization and then utilization goes back to normal 3-4 active calls.

Thanks for any input you may have.


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Nicholas Matthews Wed, 12/17/2008 - 12:45
User Badges:
  • Red, 2250 points or more

You'll want to run 'debug isdn q931' on the gateway to see if this is a false alarm from the alarms, or something funky with monitoring.

akascarface Sat, 12/20/2008 - 16:56
User Badges:

Im haveing the same problem! Its freaky. I noticed it happens when a call comes in to a unassigned DID. ISDN should be sending back unallocated/unassigned number but instead the call just stays connected infinitely and the channels incrememnt until all 23 are gone. If anyone know the solution please help. My ios is 12.4(20)T

mlabuguen Fri, 01/23/2009 - 11:25
User Badges:

I rebooted my CUCM box and the problem has since gone away.


This Discussion