Help! Calls dropping on PRI

kc4ixi · ‎07-20-2005

I am intermittently dropping inbound calls on our PRI. The error messages I am receiving in the isdn debug are 0x8092 - no user responding, and 0x80a9 - temporary failure. If the caller tries to call back a second time it usually goes through fine. The gateway is a 2651XM with a 1MFT card. Any help on determining if it is my problem or the telco would be greatly appreciated.

teodorgeorgiev · ‎07-20-2005

Well, I am 90% sure where your problem comes from.

Your Telco is configured their switch for the so called "ISDN layer 2 on demand". After being idle for particular period (idle = no call attempts in any side), the PSTN switch will drop the connection at layer 2. Then, if you make a call attempt it will fail, because the ISDN link (L2) is not up. The second call will pass through, because the ISDN layer 2 negotiation will complete.

Try the "isdn bcac" command or talk to your Telco.

costephe · ‎07-20-2005

You need to collect a debug isdn Q931 and post that here so the direction and codes can be viewed.

The No user responding is very self evident.