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voice calls drop after 10 seconds


Hello all,

I've an issue using a 3845 router as a voice gateway.

Internal voip calls are placed through a call manager 6 and external calls go through an E1 PRI interface.

Users claim that after ten seconds of two-way audio conversation the call is automatically dropped. After some debug I discovered the router is sending the ISDN DISCONNECT message after 10secs not the PSTN.

I attached a show run and a debug isqnd q931 of a dropped call. Calling numìber is 00000 called is 46299.

Llet me know if you need more shows or debug.

thanks and regards

Modified by lorenz84gDD The issue is mainly on incoming calls from the pstn. And I get the release cause: *Feb 16 11:02:52.342: ISDN Se0/0/0:15 Q931: TX -> DISCONNECT pd = 8  callref = 0x9DBB      Cause i = 0x80AF - Resource unavailable, unspecified

------- have a look to my blog
4 Replies 4

I have same issue with E1 in a 2951 (IOS 15.0), ramdomly calling to same PSTN numbers they works ok, sometimes we receiving RESOURCE UNAVAILABLE, al 10 second we receive fast busy signal....we tried everything..but nothing works...

Do anybody has a clue for this?


are all the time slots on the pri available?

When you try to use a resource that is not available, in this case a pri slot, you get what you described.

Please post a debug isdn q931 of this error.


------- have a look to my blog


What do the CUCM traces say?  You can also enable cch323 debugging on the gateway to see if CUCM is sending the disco first.  In my experience esource unavailable usually indicates a DSP, MTP, Xcoder issues that I have seen.  Fast Start enabled?

You can post the debugs and/or traces here.



i can see Cause i = 0x82AF - Resource unavailable, before Cause i = 0x80AF which means the organating code point is your telco .Please raise a ticket with your telco.

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