Possible causes of stuck channels with FreePBX 12 and Asterisk 12

This has been happening for a while now, but it is fairly infrequent, so I am just getting around to posting this question.

What are possible causes of stuck channels? Where should I look to debug this?

I have several extensions that on different occasions have ended a call but left the channel open. The BLF for that extension stays busy and the channel stays stuck until the system is rebooted. I have tired a few cli commands such as channel request hangup to no avail. The only remedy is a reboot.

I am using PJSIP for the extensions and the endpoints are all Cisco SPA 5XX series. I have seen posts about stuck channels in Asterisk 1, but nothing in more recent versions such as 12. From what I can see in those cases it was a bug that has since been fixed. As I have not seen any reports for current versions, I am thinking this is a configuration issue, but I do not know where to look to pinpoint it.

You don’t need to reboot your machine. A simple ‘core restart now’ will give you a full restart of asterisk without the need to have the entire machine reboot.

I’m interested to hear this though. Can you paste a ‘core show channels’ when a channel is in a hung state, please?

I believe I have tired that as well, but I am not certain. I will definitely try it the next time. I’ll also get the core show channels output.

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I got another stuck channel. Here is the output of core show channels

Channel Location State Application(Data)
PJSIP/109-00000091 (None) Up AppDial((Outgoing Line))

I will try core restart now off-hours and let you know how it works. I appreciate your help.

core restart now did work. I must have mistaken it for another command earlier.

This is a big help as I can now correct this without a full reboot. Thank you!

Wanted to give this a bump. I assume that whatever is causing this would be logged. I’m hoping I could get some suggestions on where to look and what to look for. I’ve gone through the Asterisk log files for the times that this has happened, but nothing jumped out to me.

You can do ‘core show channel PJSIP/[PUSH TAB]’ … when you push tab it’ll expand out to the current list of active channels, so do a show channel on one of the hung ones. Paste it here (it’ll be long, wrap it in <code> … </code> tags)

I can’t guarantee any help, but, it can only help!

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Thanks a lot. Will do.

Here is everything I tried. I didn’t get any long results…Am I misinterpreting something?

localhost*CLI> core show channel PJSIP/[PUSH TAB]
Usage: core show channel <channel>
Shows lots of information about the specified channel.

localhost*CLI> core show channels PJSIP/[PUSH TAB]
Usage: core show channels [concise|verbose|count]
 Lists currently defined channels and some information about them. If
 'concise' is specified, the format is abridged and in a more easily
  machine parsable format. If 'verbose' is specified, the output includes
  more and longer fields. If 'count' is specified only the channel and call
  count is output.
	The 'concise' option is deprecated and will be removed from future versions
	of Asterisk.

localhost*CLI> core show channels
Channel              Location             State   Application(Data)             
PJSIP/109-000001c8   (None)               Up      AppDial((Outgoing Line))      
0 active channels
0 active calls

localhost*CLI> core show channel PJSIP/109-000001c8
PJSIP/109-000001c8 is not a known channel

You’re not pushing tab.

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Lol. Can’t believe I didn’t pick up on that.

Here is what I get pressing tab.

localhost*CLI> core show channel PJSIP/109-000001c8 
PJSIP/109-000001c8 is not a known channel

You’re confused. Re-read my original message.

The tab button just saves you typing, that’s all.

I think I got it right that time. I typed core show channel PJSIP/, pressed tab which completed it with the hung channel, and pressed enter. It looks to me like core show channel cannot find the hung channel.

Well that is, for sure, an Asterisk bug then.

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I’ll put a bug report in. Thank you for all your help with this.

A_I - did you get a resolution to this bug or do you have a number I can track?

Just wanted to add my 2 cents here, I’m experiencing the same thing:

PJSIP/974-00000a0d (None) Up AppDial((Outgoing Line))
PJSIP/977-00000ae1 (None) Up AppDial((Outgoing Line))

asteriskCLI> core show channel PJSIP/974-00000a0d
PJSIP/974-00000a0d is not a known channel
asterisk
CLI> core show channel PJSIP/977-00000ae1
PJSIP/977-00000ae1 is not a known channel

Channel hangups won’t work. (as they aren’t known channels)
BLF lamps stuck on for these extensions
Asterisk 12.6.1 - SPA504G on the above two extensions

Thanks.

I did not find a resolution. I’ve been meaning to put a bug report in with Asterisk, but I have not done so yet. Their bug tracking site requires a client certificate, and I haven’t figured out what I need to do to gain access.

It doesn’t need any thing special, just create an account.

Took another look after seeing your post, and it was user error. My JS blocker was preventing it from loading fully, but I was getting this message as well, so I just assumed that was the cause and didn’t even think about the JS. Just submitted the bug. Thanks again for all your help on this, Rob.

I do now…it is ASTERISK-25035. https://issues.asterisk.org/jira/browse/ASTERISK-25035

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