[Asterisk-Users] Problems with stuck PRI channel

[Korey Chapman]

I haven't seen anything about this is the archives, so here we go. 
Sorry, its a long one.

My setup:
Dual Xeon 2.4 GHz.
One TE410P card.
Span 1 populated with a PRI.
Span's 2-4 empty.

zaptel.conf:
span=1,1,0,esf,b8zs
bchan=1-23
dchan=24
loadzone = us
defaultzone=us


I'm currently having a problem where one of our PRI channels seems to
keep a call even after it is hung up.  We have only seen it happen with
one channel at a time, but its not the same channel every time.  The
channel continues to receive calls from the telco (we are in Qwest land
here) and Asterisk is dumping them.

Here is the message from asterisk when a new call comes in on the busy
channel:
"Ring requested on channel 13 already in use on span 1.  Hanging up
owner."

The state of the channel stays the same after this error occurs.

The channel data for that zap channel shows the channel still connected
to a SIP phone.  The phone is not in use and does not have anything on
hold.

I have attempted to kill the channel with "zap destroy channel", but it
does not appear to work.  Doing some operations on the console appears
to cause asterisk to die.  When asterisk returns to normal operations
the channel is clear (of course all of our calls are gone too).

I looked at zttool, it doesn't show any IRQ misses or alarms.

This has been happening once a week, but suddenly has become once a day.
I'm at a loss.

We just did a full update of asterisk, libpri, zaptel, and zapata within
the last week.  The problem is still occurring after the update.


Here is a pri debug from during an incident, phone number obscured to
protect the innocent :)

< Protocol Discriminator: Q.931 (8)  len=35
< Call Ref: len= 2 (reference 5160/0x1428) (Originator)
< Message type: SETUP (5)
< Bearer Capability (len= 3) [ Ext: 1  Q.931 Std: 0  Info transfer capability: Speech (0)
<                              Ext: 1  Trans mode/rate: 64kbps, circuit-mode (16)
<                              Ext: 1  User information layer 1: u-Law (34)
< Channel ID (len= 5) [ Ext: 1  IntID: Implicit, PRI Spare: 0, Exclusive Dchan:0
<                        ChanSel: Reserved
<                       Ext: 1  Coding: 0   Number Specified   Channel Type: 3
<                       Ext: 1  Channel: 22 ]
< Calling Number (len=14) [ Ext: 0  TON: National Number (2)  NPI: ISDN/Telephony Numbering Plan (E.164/E.163) (1)
<                           Presentation: Presentation allowed of network provided number (3) '818763XXXX' ]
< Called Number (len= 6) [ Ext: 1  TON: Subscriber Number (4)  NPI: ISDN/Telephony Numbering Plan (E.164/E.163) (1) '853' ]
-- Making new call for cr 5160
-- Processing Q.931 Call Setup
-- Processing IE 4 (Bearer Capability)
-- Processing IE 24 (Channel Identification)
-- Processing IE 108 (Calling Party Number)
-- Processing IE 112 (Called Party Number)
Mar 23 12:50:12 WARNING[1167306032]: chan_zap.c:6271 pri_dchannel: Ring requested on channel 22 already in use on span 1.  Hanging up owner.
NEW_HANGUP DEBUG: Calling q931_hangup, ourstate Call Present, peerstate Call Initiated
> Protocol Discriminator: Q.931 (8)  len=9
> Call Ref: len= 2 (reference 37928/0x9428) (Terminator)
> Message type: RELEASE COMPLETE (90)
> Cause (len= 2) [ Ext: 1  Coding: CCITT (ITU) standard (0) 0: 0   Location: Private network serving the local user (1)
>                  Ext: 1  Cause: Requested channel not available (44), class =Network Congestion (2) ]
NEW_HANGUP DEBUG: Calling q931_hangup, ourstate Null, peerstate Null
NEW_HANGUP DEBUG: Destroying the call, ourstate Null, peerstate Null


Any help is appreciated.

Sincerely,
Korey Chapman