Calls Ending Randomly Mid Conversation

Hi. I’m using FreePBX For some time we’ve been having a problem where calls just end mid conversation, even though neither party has hung up. It’s quite rare, maybe only one in every few hundred calls has the problem, but it’s been present for quite a while now. It doesn’t seem to be linked to a particular phone type, as it happens on both our Cisco desk phones and Yealink wireless phones. I’ve managed to get a log of it happening. See below:

(Edit: removed irrelevant log)

If anyone can help in any way it would be very much appreciated. Thank you.

CDR Report of the same call if it helps

(Edit: removed irrelevant log)

The Yealink phones display “Call Ended” and the Cisco phones display “Busy” when it happens also.

Looks like your DAHDI phone hung up the call. Check to see if your having problems with that card.

I set debug to 3 and got the following when it happened again if it’s of any use:

(Edit: removed irrelevant log)

This makes it look like the Cordless Phone hung up.

Have you tried setting this phone up with Chan-SIP?

There were issues with some cordless phones that we discussed a few months ago. For example, if this phone is jumping between Access Points, or if the network connection is lagging, you could be having a network issue.

It’s also possible that the phone isn’t playing nice with PJ-SIP.

There are just too many variables to get closer. Look at just the SIP DEBUG output isn’t really helping a lot, since it’s just showing the SIP part of the conversation. Look in the /var/log/asterisk/full log and see if you are getting long ping times to the phone - it could be something as simple as a setting in the channel driver or the phone.

[2017-02-01 21:14:40] DEBUG[28194][C-00000012] dsp.c: Requesting Hangup because the busy tone was detected on channel DAHDI/2-1

Busy tone?

After a bit of browsing I think I see what’s happening. It’s incorrectly thinking that the other party has hung up, which is triggered by a certain noise? (Correct me if I’m wrong).

If so, this makes sense as it has never been able to detect hangups properly. I’ve just lived with it for the past few months.

I’m using a TDM410P connected to 4x FXO lines in the UK (I think this is where I struggled when setting it up as I could only find solutions for FXO lines in the US which work differently to mine).

Be aware that mostly that is for BT other carriers use more normal call supervision and CID info watch out for your busydetect and be specific for the cadence you are getting from your carrier if your provider can’t or won’t tell you how they provision their lines.

Thank you dicko, that’s exactly the type of article I needed but failed to find when I set the system up. Fortunately I do have BT lines (4 POTS lines with the same number for each line). I’ll have a go at implementing it as soon as I can.

Until I can get the hangup detection to work properly, is there a way that I can disable the “Requesting Hangup because the busy tone was detected on channel” feature, just to prevent the random hangups happening? Thanks.

Never mind, got it.