Solved Call is dropped on failover from one Ring Group to another

[Foiler]

Our incoming calls to the main phone number go to one ring group, then fail-over if unanswered to a second ring group, then fail-over to a third, then to a voicemail.

This works fine when testing internally ie dial the first ring group directly, and the call progressively falls over when unanswered as above, and finally to voicemail.

However, incoming calls from an outside source are dropped at the fail-over of the second ring group ie the second fail-over is never achieved for an incoming call, let alone the third fail-over to voicemail.

The logs show this:
Call to <sip:[email protected]:0> has failed; Cause: 487 Request Terminated/INVITE from 192.168.xxx.xxx:5060

Is this a Trunk problem because the system works ok with internal testing? but the log suggests the call was terminated by the target of the fail-over?

 

[leejor]

There is no security reason to X out a local IP. What device did that IP belong to, or was it that of the server? What type of trunks are you using? Without additional information, my first guess, would be that it might be a re-invite issue.

 

[Foiler]

ok fair enough leejo .. here is the log ..

01/20/2021 12:37:31 PM - [CM503003]: Call(C:7): Call to <sip:[email protected]3cx.xx:0> has failed; Cause: 487 Request Terminated/INVITE from 192.168.139.101:5060
01/20/2021 12:37:20 PM - [CM503003]: Call(C:7): Call to <sip:[email protected]3cx.xx:0> has failed; Cause: 487 Request Terminated/INVITE from 192.168.139.100:5060

The 3CX PBX is on the same LAN as the phones, and the address xxxx.my3cx.xx is resolved to 192.168.139.50 by the dns of the network.

 

[ChrisC_3CX]

@Foiler

Just so we first get a better idea of your setup, please provide the information mentioned in this post: https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/#post-292742

Also, try decreasing the first Ring Group's ring time to something like 10 seconds and let me know if you notice any differences when receiving an external incoming call. Keep an eye on the ring time of the call before it drops and check whether it always drops after a set amount of seconds.

 

[Foiler]

just a quick update .. I tried varying the ring times for each group, and find that the failovers are not limited, but the total ring time is .. I can go back and forward between two ring groups every 2 secs but the call ends after approx 25 sec, same for a 15 sec ring duration setting.

We have the latest 3CX software running Debian Linux host and on same LAN as Fanvil X3U phones, and provisioning is set to local.

I have maybe a non-standard dns setup .. the phones are all set to find the PBX on the xxxx.my3cx.xx interface, but this address is set in the local dns server (ie the router) to resolve to 192.168.138.50 .. whereas the public resolution of that address is in fact a public IP address .. we set it up this way to give our phones flexibility of a LAN pbx, with a standby pbx on same LAN, or a WAN pbx.

 

[ChrisC_3CX]

Hey @Foiler,

Based on the fact that the external call ends after a set amount of seconds, I do think this may in fact be an issue related with the SIP Trunk. I assume answered calls last longer so this may be a case where the call is timing out if not answered within a specific time.

What Trunk Provider or Gateway Make/Model are you using?

 

[Foiler]

yes absolutely .. there does not seem to be a time limit on answered calls .. will discuss with VoIP provider

And the DNS setup I have .. is there any chance that the PBX is objecting to that? .. there is an error showing on the Dashboard "Error: IP address mismatch"

 

[Foiler]

Eek .. there is a ring timer setting on the VoIP provider trunk and this was set to 20 sec .. all sorted now.

Many thanks to you Chris for leading me onto the variable ring times path to prove this wasn't a failover thing.

 

[ChrisC_3CX]

@Foiler

You're very welcome! Glad everything is now sorted!
Just as an FYI, your DNS configuration sounds fine and should not cause any issues.