[Asterisk-Users] Strange PRI lockup

[Johann]

We are currently using Asterisk 1.0.8 and noticing a rather odd problem 
that occurs roughly during the middle of the day sometimes.  It seems 
that Asterisk and Bellsouth are getting out of sync somehow on the the 
status of the PRI channels.  I get warnings messages like:

Jul 18 10:50:24 WARNING[744]: chan_zap.c:7585 pri_dchannel: Ring 
requested on channel 0/1 already in use on span 1.  Hanging up owner.

The other channels continue to work flawlessly.  It is always different 
which channel the problem is with, but it is a low numbered channel that 
is active from an incoming call.  Outbound calls use a high numbered 
channel and can continue while a low numbered channel is having a 
problem.  The time is usually around the middle of the day when there 
are a lot of inbound calls as well.  It has happened about 4 times since 
upgrading to Asterisk 1.0.8(we use to be on a CVS build from Feb).

I've talked with Bellsouth and from their end everything is normal.  
They see the channel that the call is being sent to as being open.  I 
have to kill -9 the asterisk proceses and restart it to get the pbx back 
up and fully operational.

I have used ZapScan() and checked the audio on the channels that 
Asterisk still thinks are in use and there is nothing.  I can't soft 
hangup the chanenls either.  The commands "show queues" and "show 
agents" return nothing at all.  Agents are not able to login or logout 
of the queue either.  The channels that have been in the inconsistent 
state have always been calls that were sent to the queue as well.

Any ideas on why this may be occuring and a possible fix?

--johann