Incoming calls not being routed to extension

[njp]

Hello,

System: 3CX v15
Gateway: Patton SN4112 (1 line only)
Phones: 40 x Yealink T42G
Switch: HP 1920-48G PoE
Router: Drayek 2860

Currently if anybody rings in via the analog BT PSTN, the call is routed to one specific extension. Everything has been working fine for a few weeks, all calls have successfully been dialing in on the extension configured as inbound (20 - 30 calls per day). Everybody is able to also ring out via configured dialplan (dial 9 before number).

As of yesterday, external calls aren't going through to the extension anymore. The call log shows the calls coming in onto the extension but the last 'Talking' column just shows 'Not Answered'. I'm ringing in right now via my mobile to test and the IP phone is just not ringing. The Patton gateway shows the FXO LED blink whilst I ring in so the call seems to be coming in. Everybody is able to ring out successfully so it's just the incoming call.

I've so far tried changing the inbound to a different extension but this hasn't worked. Nothing has been messed around with at the site (server room is under lock and key). Network is fully operational, the Patton is showing a successful link to the PBX.

How can I start to try and diagnose this? Has anybody else had a similar issue where the inbound calls just stop routing in out of the blue?

Any help is appreciated.

 

[njp]

In the activity log I'm getting this whilst trying to ring in from the PSTN:

02/01/2017 11:58:20 AM - Leg L:30.1[Line:10000<<anonymous] is terminated: Cause: BYE from PBX
02/01/2017 11:58:20 AM - [CM503020]: Call(C:30): Normal call termination. Call originator: Line:10000<<anonymous. Reason: Not found
02/01/2017 11:58:20 AM - [CM503014]: Call(C:30): No known route from Line:10000<<anonymous to target: <sip:181@:63729>
02/01/2017 11:58:20 AM - Call(C:30): from Line:10000<<anonymous to 181 doesn't match any known extension number.
02/01/2017 11:58:20 AM - [CM503010]: Call(C:30): Making route(s) from Line:10000<<anonymous to <sip:181@:63729

It's saying extension 181 doesn't match a known number, but the extension is registered, and the corresponding IP phone is online and registered (and still being used internally without problems).

 

[njp]

Okay so it's all miraculously started working again, and the calls are being correctly routed to the corresponding IP phone as before.

This is worrying because I have no idea what I have done to fix it. I had:

• Restarted the 3CX server and Patton gateway, and neither had fixed the issue.
• Checked services, all were running.
• Restarted router, didn't fix the issue.
  
• Reconfigured the Patton gateway via 3CX, and this didn't fix the issue.
• Clicked into the corresponding extensions, and clicked OK. no fix.

The only other thing I can remember doing is running the Firewall Test prior to everything working again.

Is there any information on this or why it could have happened out of the blue, and what rectified it? My client is worried as this can happen at a moment's notice, and is now reluctant to purchase a license unless there's at least a technical reason for why it happened, or a maintenance procedure to follow frequently to avoid the issue.

 

[YiannisH_3CX]

Hello @njp
Do you have any DID's that are 3 digits long?

 

[njp]

Hello @njp
Do you have any DID's that are 3 digits long?

Many thanks for your reply.

Nope, just the one DID '000000' which corresponds to the one external line that we have coming in from the Patton. This is the same as Main Trunk No. that was set to 000000 within the gateway config. Not sure if this is correct, but regardless everything had been working fine for weeks.

 

[kflorian]

@njp,

"The only other thing I can remember doing is running the Firewall Test prior to everything working again."

Thank you for taking the time to post your problem and this fix. Running Firewall Test solved a similar problem for me.

 

[FCGScott]

We just ran into this issue with incoming calls on v. 15.5.3849 "no known extension number". We are running the Linux ISO version behind a SonicWALL firewall. Running the firewall test on 3CX resolved the issue. We had tried restarting the 3CX server twice, wondering if this is just a traffic flow issue with certain firewall settings? Outbound calls were successful as were inside (extension to extension) calls.