Incoming Calls Collide with Each Other

@david55 Thank you for your comments. If I understand you correctly, this behavior is not desired, but expected in certain instances. I understand that my problems may be an issue with my telephone company. We did not have this problem before changing PBXs from our older AVAYA to the FreePBX system. Is the newer hardware more sensitive to this behavior?

@dicko You helped me get started with the DAHDI groups a few months ago (thank you). In Connectivity>Trunks>dahdi Settings, Line 3 is set as G0, Line 2 is set as R0, and Line 1 is set as g0. I have confirmed that calls come in on Line 1 when dialed directly, line 2 when line 1 is busy or if it is direct dialed, and line 3 and 4 only when they are direct dialed. We are not having glare issues on outbound and inbound calls (thanks to your aforementioned help) as long as all four of our lines are not busy. Right now, the problems occurs only when two callers are calling at the same time. Is this what you’re asking, or is there a config file I could look at somewhere?

My comments were certainly based on the assumption that they were routing the call back to the PSTN, as that seemed to me to be the only sensible explanation of the symptom. Especially if that is not the case, I think we need to see the logs, to understand what is actually happening.

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I would encourage you again to double check for ‘split pair’ wiring of your lines where the tip of one line is paired with the ring of another.(It could be before your mpoe . i.e. the telco ) . What was on the telco blue pair?

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With the calls bridging before the PBX sees the call, I don’t see a way that this isn’t a wiring problem. I accidentally punched down and bridged two tips together when I was wiring a building back in the '80s and caused a situation similar to this.

IMO, this thread is going nowhere because no real troubleshooting has been done.

Approximately how often does this occur?
About how many calls do you receive per day?
How are calls normally answered (IVR, ring group, queue, etc.)?
Can you cause this trouble at will, e.g. by calling in from two mobile phones at the same time?
Have any employees experienced the trouble when calling in?

You can view 5000 lines in Chrome without issue. Or, copy /var/log/asterisk/full to your PC and use an editor to select the desired section.

OK. Thank you. I am working on getting the logs together now. This problem occurs almost daily. Calls are normally sent to our reception ring group, then to an IVR for clients to leave messages. I have not been able to duplicate this problem, but employees have complained that they experience what sounds like a hangup when they call in from time to time.

I am offsite right now, so I cannot physically inspect the cabling. As I said the logs are coming. Is there a way I can remove the caller ID name and the extension name from the file?

Whatever tool you have that has a search and replace function.

Ask them to note the time, so you can easily find the relevant log section.

Are these all in-office extensions? If not, how are they connected?

@dicko I will certainly run through my wires the next chance I get.

@Stewart1 @david55 @lgaetz
Here is one of the calls: [Call1]
Here’s the other one: [Call2]

The phones ring all day. We have between 250 and 300 calls a day total.

Are these all in-office extensions? If not, how are they connected?

Yes, these are all in office extensions.

Ask them to note the time, so you can easily find the relevant log section.

I have done so. I thought I would open a new thread after I get this one figured out for that problem. Should I deal with that one here?

I am certainly open to this being a human error / clumsy / wrong button being pushed problem.

[2021-06-07 12:48:30] VERBOSE[24234][C-00000093] pbx_builtins.c: Goto (ext-group,420,1)
Ring group 420? Is that where the stoners hang out?

[2021-06-07 12:48:44] VERBOSE[24234][C-00000093] app_dial.c: Now forwarding DAHDI/2-1 to 'Local/[email protected]' (thanks to PJSIP/451-00000199)

And one of them sent the call to the parking lot? 451 appears to be a Zulu extension. If it’s mobile, perhaps this happens accidentally when taking the phone out of the pocket? If it’s desktop, does the layout make it easy to do by mistake?

This is no longer looking like glare. It looks like you are unparking a call which isn’t the one you parked, and this unpark is result of call forwarding set on the actual extension device at PJSIP/451, not something within FreePBX. You also need to find where the call gets parked in parking lot 71, Maybe another destination device is call forwarding to your park a call extension?

Ring group 420? Is that where the stoners hang out?

Pretty naive here. That’s kind of funny. I’ll tell my reception team that I gave them that group number, they’ll probably get a kick out of it.

I would like to get SangomaConnect / Zulu set up, but one thing at a time. 451 is an actual Sangoma S505 phone, not a softphone. How do I fix that?

Would you explain “unparking a call that I didn’t park?” If a call isn’t parked, how can it be unparked. I think I’m missing some terminology. What does “where the call gets parked in parking lot 71” mean? I have three slots set up, do you mean slot 71, 72, or 73? Are they parking two calls together?

Thank you for your patience.

Sorry that I misinterpreted the log. Unfortunately, I know almost nothing about Sangoma phones. I know that if you blind transfer an incoming call to 71, it gets parked. If you then attended transfer another incoming call to 71, that unparks the first call and the two incoming calls are connected together.

You could use pjsip logger to see the SIP transactions that underlie whatever buttons were intentionally or accidentally pressed. When a phone is ringing, what options are presented? If one of the options is ‘forward’ or ‘reject’, that may have been preprogrammed to effect a park action. Or, if you have a parking BLF key set up, it’s possible that pushing that while the phone is ringing will park the unanswered call.

If all else fails you can make some test calls in and see if any option results in answering the call and immediately parking it.

I meant that it was expecting to find a particular call parked in the slot but a different call was actually parked there.

Something must have parked a call in slot 71. I meant find out, from the logs, what put the call there.

The call is being specifically redirected to pick up the call from slot 71.

That’s not physically possible; the data structures can only store one channel.

It appears that the extensions involved in your two log fragments have call forward unconditional set to 71 (I suppose it could be call forward busy, if the phone can do that). That doesn’t seem a sensible thing to do.

It also seems likely that another device is set to do similarly to the park a call virtual extension (which I guess is 70).

The “forwarding thanks to …” message indicates, for chan_sip, that the phone returned a SIP 302 Moved Temporarily response, together with a new extension number to call, which is how a phone would implement unconditional (or possibly busy) forwarding.

Thank you for helping me track this down. May I assume that the offending extension is in Ring Group 420? I’ll look into the call forwarding thing a bit more. It is disabled via the extension manager in the web interface. How can I get 451 to not be a Zulu extension.

I’m talking about the phone itself. The S505 has a native call forwarding feature that doesn’t require FreePBX. Looking at the S Series user guide, details are on page 21 (PDF page 31). This is for Revision 1, from April 2017, of the user guide.

It is possible there are also ways of changing this remotely, but someone else will need to chip in with those.

Thank you for all your help! I plan to look at extension 451 as soon as I return to the office.
I just called and experienced what I had indicated earlier for an employee. If I am reading this right, extenstion 421 (uses a headset) answers the call and then does something that hangs up. Am I interpreting this correctly?

Here is the log: Answer / Hangup

In https://pastebin.com/xbFLaKfL virtual extension 420 causes, amongst others, 451 to be called. 451 doesn’t answer, but instead forwards the call to 71, using SIP forwarding, rather than FreePBX forwarding.

In https://pastebin.com/4iYMkMYw 421 answered the call, and 28 seconds later, one side or the other ended the call. There isn’t enough detail to see why, but 28 seconds is a typical timeout for failing to receive an ACK from Asterisk, in response to OK from the phone, which often happens with broken NAT or over zealous firewalls. This should be clear from pjsip set logger on, and probably also so if you turn up the verbosity.

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In https://pastebin.com/bTNYj65U , the call was answered on extension 421 at 09:28:17. Unfortunately, the log ends within that second, so the section related to the trouble is not present.

BTW, when you paste logs, we prefer you to use pastebin.freepbx.org . It’s ok to post content on another service, but be sure that the expiration is set to ‘never’, so future readers of the thread can follow along. Don’t post content on a server with enforced expiration, or one that requires the reader to log in (and be tracked). If you have content that cannot be posted directly here or pasted, make a .tgz file and attach it to your post.

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Thank you. Armed with the information contained within the logs, I had a discussion with my reception team who thinks they may be hitting a horizontal soft key button (specifically the transfer) sometime when they answer. I would like to disable it, but I can’t figure out how to set it in EPM. I set the button, but the phones don’t revert back to what they had before - the changes are not reflected on the phones. I posted this problem in the phone forum a couple of months ago and did not hear back. Link to other discussion

I originally bought the Sangoma Phones to support the company that is making FreePBX possible. After having this problem and another, I’m starting to regret that purchase .
If the problem persists, I’ll look at a pjsip log to see if we can tell what buttons are being pushed. I need a very basic “how to” on this. My searches have turned up some instructions, but they assume I already have a CLI on the phone. Is there a piece of software I need to install?

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