asterisk users - May 2012 - hangup problem on T1 span

Hello all,

I'm trying to solve a problem on a T1 span setup wherein calls are
apparently not hanging up properly.

The system in question is using a Xorcom Astribank with 1 full and 1
partial T1 span, and running Asterisk 1.4.36.

The symptom is that when a call hangs up on a DAHDI channel (according to
Asterisk), and another outgoing call tries to open a new channel on the
same line as the hung-up call within approximately a minute of the hangup,
the new call gets a congestion notice ("all circuits busy") from
asterisk. After about a minute passes after the hangup, the line becomes
available again. So it seems like the channels are not hanging up when
Asterisk tells them to, and Asterisk doesn't know it.

I suspected a signaling issue, and this appeared confirmed when I
discovered that the signalling was set in chan_dahdi.conf as "fxs_ks"
(this
installation had been converted from analog lines by another company; I
guess that was an oversight?).

So I changed it to pri_cpe, as my reading of the docs indicated was proper.
After this change and restarting everything, though, the symptoms persist.
So I figure that either my reading of the docs is wrong (and therefore
pri_cpe is not the right signaling) OR something totally unrelated is going
on.

Can someone please clue me in here? I am a bit at a loss. Let me know if
you need further information about the system/environment.

Regards,

Stephen J Alexander
MPBX, LLC
http://mpbx.com
832-713-6729
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On Wed, May 02, 2012 at 11:18:54AM -0500, Stephen J Alexander
wrote:
> Hello all,
> 
> I'm trying to solve a problem on a T1 span setup wherein calls are
> apparently not hanging up properly.
CAS or PRI?
> 
> The system in question is using a Xorcom Astribank with 1 full and 1
> partial T1 span, and running Asterisk 1.4.36.
> 
> The symptom is that when a call hangs up on a DAHDI channel (according to
> Asterisk), and another outgoing call tries to open a new channel on the
> same line as the hung-up call within approximately a minute of the hangup,
> the new call gets a congestion notice ("all circuits busy") from
> asterisk. After about a minute passes after the hangup, the line becomes
> available again. So it seems like the channels are not hanging up when
> Asterisk tells them to, and Asterisk doesn't know it.
> 
> I suspected a signaling issue, and this appeared confirmed when I
> discovered that the signalling was set in chan_dahdi.conf as
"fxs_ks" (this
> installation had been converted from analog lines by another company; I
> guess that was an oversight?).
The signalling and such is probably set in
/etc/asterisk/dahdi-channels.conf so that setting does not matter.
> 
> So I changed it to pri_cpe, as my reading of the docs indicated was proper.
> After this change and restarting everything, though, the symptoms persist.
> So I figure that either my reading of the docs is wrong (and therefore
> pri_cpe is not the right signaling) OR something totally unrelated is going
> on.
> 
> Can someone please clue me in here? I am a bit at a loss. Let me know if
> you need further information about the system/environment.
What is the output of 'dahdi show channel N' for one such a
"bad"
channel when not in a call? Are you sure it's not in a call? See the
output of 'core show channels'.


-- 
               Tzafrir Cohen
icq#16849755              jabber:tzafrir.cohen at xorcom.com
+972-50-7952406           mailto:tzafrir.cohen at xorcom.com
http://www.xorcom.com  iax:guest at local.xorcom.com/tzafrir