Summary:ASTERISK-16164: MGCP Zombie Channel
Reporter:Juan Settecase (juanctkc)Labels:
Date Opened:2010-05-28 11:11:07Date Closed:2011-07-27 14:47:45
Versions:Frequency of
Environment:Attachments:( 0) asterisk.zombie.debug.log.txt
Description:sometimes are show zombies mgcp channels on asterisk . phone client's dont be hangup, and latter asterisk don't answer anything to "restart now" and we can't do other calls from anothers telephones. I have to do and "soft hangup" for that zombie channel to asterisk work correctly again.

show channels
Channel              Location             State   Application(Data)            
MGCP/aaln/1@0015cef9e074.mta-0<ZOMBIE> s@macro-stdexten:1   Down    Dial(MGCP/aaln/1@0015cef9e074.

There is a bug? what can i do to check don't happen again?
Thanks for all.
Comments:By: Juan Settecase (juanctkc) 2010-05-31 09:50:34

Same problema again. More info:

------ show channel MGCP/aaln/1@0015ceb8eec8.mta-0<ZOMBIE>  -----
-- General --
          Name: MGCP/aaln/1@0015ceb8eec8.mta-0<ZOMBIE>
          Type: MGCP
      UniqueID: 1275265517.11
     Caller ID: 3498282012
Caller ID Name: 3498282012
   DNID Digits: (N/A)
         State: Down (0)
         Rings: 0
 NativeFormats: 0x4 (ulaw)
   WriteFormat: 0x4 (ulaw)
    ReadFormat: 0x4 (ulaw)
WriteTranscode: No
 ReadTranscode: No
1st File Descriptor: 4
     Frames in: 614
    Frames out: 2
Time to Hangup: 0
  Elapsed Time: 13h1m12s
 Direct Bridge: <none>
Indirect Bridge: <none>
--   PBX   --
       Context: macro-stdexten
     Extension: s
      Priority: 1
    Call Group: 0
  Pickup Group: 0
   Application: Dial
          Data: MGCP/aaln/1@0015ceb8eec8.mta|60
   Blocking in: (Not Blocking)

 CDR Variables:
level 1: clid="3498282012" <3498282012>
level 1: src=3498282012
level 1: dst=s
level 1: dcontext=base
level 1: channel=MGCP/aaln/1@0015ceb8eec8.mta-0
level 1: start=2010-05-30 21:26:26
level 1: duration=0
level 1: billsec=0
level 1: disposition=NO ANSWER
level 1: amaflags=DOCUMENTATION
level 1: uniqueid=1275265581.13

------ show channel concise --------

By: Leif Madsen (lmadsen) 2010-06-02 10:45:21

We will need additional information here. It is possible this could be a deadlock, but there isn't enough information to tell. There isn't a lot of support for MGCP, so you may have to find other MGCP developers elsewhere in order to move this issue forward. But for now we'll start with debugging information.

Find below some information.


We require a complete debug log to help triage the issue.

This document will provide instructions on how to collect debugging logs from an Asterisk machine for the purpose of helping bug marshals troubleshoot an issue:



Debugging deadlocks:

Please select DEBUG_THREADS and DONT_OPTIMIZE in the Compiler Flags section of menuselect. Recompile and install Asterisk (i.e. make install)

This will then give you the console command:

core show locks

When the symptoms of the deadlock present themselves again, please provide output of the deadlock via:

# asterisk -rx "core show locks" | tee /tmp/core-show-locks.txt

# gdb -se "asterisk" <pid of asterisk> | tee /tmp/backtrace.txt

gdb> bt
gdb> bt full
gdb> thread apply all bt

Then attach the core-show-locks.txt and backtrace.txt files to this issue. Thanks!
Thank you for the bug report. However I am unable to reproduce this issue. We are now going to close this report - please feel free to reopen when you have more information at hand.

By: Juan Settecase (juanctkc) 2010-06-04 08:34:25

yesterday i had to do an script that restart asterisk when zombie channels are detected because asterisk can not spend much time offline  before i will arrived.
yesterday evening, zombie channel appeared and my script restarted asterisk automatically.
i've attached specific log like it's said in http://svn.digium.com/svn/asterisk/trunk/doc/HOWTO_collect_debug_information.txt. but it seem dont help to much.
the problem appeared June 3 20:15 (log)

By: Paul Belanger (pabelanger) 2010-06-14 09:00:06

Did you forget to attach the log file?

By: Juan Settecase (juanctkc) 2010-06-15 08:07:57

I missed uploading the file.
I just upload: asterisk.zombie.debug.log.txt
In that log, the problem appeared June 13 20:25hs

Sorry and thanks.

By: Juan Settecase (juanctkc) 2010-07-26 15:20:36

the problem still persists. less consistent but still
any ideas?

By: Leif Madsen (lmadsen) 2010-07-27 08:22:43

Sorry, chan_mgcp is not well supported, so you may have to try and find a community developer who is willing to work on this problem. Otherwise you'll have to wait until time and resources are available from the development team to look at this issue.

By: Juan Settecase (juanctkc) 2010-07-27 10:02:44

what can i do with this ticket? close?
madsen, do what you want with  it ;)
if i can resolved this problem (zombie channels on mgcp) i will publish it here.
thanks for all and your time.


By: Leif Madsen (lmadsen) 2010-07-27 10:10:06

jaunctkc: sounds good! if you can solve it then feel free to post a patch or however it is solved.

We'll leave this issue open for now. Thanks!

By: Juan Settecase (juanctkc) 2010-11-11 08:26:40.000-0600

After months of work on this, i can't resolve this problem.
mgcp enpoints manufacturer says the problem that make "zombie channel"  is not your equipment or software generated

lmadsen, again thanks for all  
PD: by other way and out of context, where i can get documents write by you or where you participated? i have read a few, but i like to read more. i know its wrong ask that here, but i don't know another way to asked you. thanks for all.

By: Leif Madsen (lmadsen) 2011-07-27 14:47:45.736-0500

I'm going to suspend this for now. If someone is able to move this forward, please request a bug marshal to reopen this. Thanks!

BTW: You can access most of my documents via www.leifmadsen.com

By: Juan Settecase (juanctkc) 2011-07-28 07:48:16.199-0500

OK. Thanks for all Leif.