IOS and Android unable to make phone calls or pick up calls

[SONIQ]

Hi 3CX community,
Hoping to get some direction as I have run out of troubleshooting ideas. We experience these problems since the 3CX update in late august. Prior to that everything was working.

currently:
-unable to make phone calls from IOS and android 3cx App
-App shows as "connecting..." in the top right corner of the app
-We receive incoming calls on IOS and Android phones but cannot pick up the call.
-no problems with windows client or chrome app. All works seamlessly in the office and externally.

• 3CX Version, Enterprise Annual 16.0.655
• Server OS, Windows Server 2016 standard
• Server DNS: google DNS 8.8.8.8
• Is the 3CX Server Hosted and where? Hosted inhouse
• IP Phone Make/Model/Firmware: iphone 11 Pro,- IOS 14.01
• Provisioning Method: Local / VPN / STUN / SBC - local
• Trunk Provider or Gateway Make/Model - Breezeconnect
• Has the Firewall Checker passed: Yes all passed
• 3CX APP version on IOS: 16.1.5.43

Troubleshooting steps so far
-Tried on several models of iphones, with IOS 14.0.1
-Tested on internal wifi as well and LTE from home broadband
-Ran firewall tested on 3CX - everything passed
-Double checked firewall all settings based on the following links: https://www.3cx.com/docs/manual/firewall-router-configuration/, https://www.3cx.com/docs/sonicwall-firewall-configuration/
-Restart of 3CX server
-uninstalled antivirus
-disable windows firewall
-created new extension with default settings
-Checked and confirmed external FQDN resolves to correct IP address
- tested ticking/untick "PBX Delivers Audio, Supports re-invites, Support 'Replaces' header" under extension -> options ->Troubleshooting
- untick "Disallow use of extension outside the LAN (Remote extensions using Direct SIP or STUN will be blocked) "
- tick " Accept Push Notifications"
- Tried various combinations of SIP Transport and RTP Mode settings under Extension - >Phone Provisioning -> Network

Thanks for reading and any help would be high appreciated! Cheers

 

[rgruber]

It looks like you have done extensive testing. What were your results when you said tested on internal wifi and LTE? Have you tried to create a new (test) user and provision the iphone app on that new user? I know you said your firewall tested fine, but confirming you have these ports open?
https://www.3cx.com/docs/ports/

 

[leejor]

Do you use any SBCs? It would appear that , while 3CX is able to send a PUSH message to the phone, and knows how to reach it, the phones are not able to communicate with 3CX. Perhaps this is only happening in one direction.

If you had another device that also used that Tunnel, you may be able to determine what is blocking. I have to assume that it is some sort of firewall setting, even though, you say that the 3CX Firewall checker is passing. Is the 3CX Activity Log showing anything when the phones initially register?

 

[SONIQ]

It looks like you have done extensive testing. What were your results when you said tested on internal wifi and LTE? Have you tried to create a new (test) user and provision the iphone app on that new user? I know you said your firewall tested fine, but confirming you have these ports open?
https://www.3cx.com/docs/ports/

I get the same result on the iphone when on internal and LTE. 3CX apps shows as connectin, cannot make outbound calls, can receive the call but not answer.

Yes, Ive tried creating a new user and provisiong the iphone app for the user without any success.

Yup, check the firewall against https://www.3cx.com/docs/ports/ and confirmed all the ports are open except for 2528

 

[SONIQ]

Do you use any SBCs? It would appear that , while 3CX is able to send a PUSH message to the phone, and knows how to reach it, the phones are not able to communicate with 3CX. Perhaps this is only happening in one direction.

If you had another device that also used that Tunnel, you may be able to determine what is blocking. I have to assume that it is some sort of firewall setting, even though, you say that the 3CX Firewall checker is passing. Is the 3CX Activity Log showing anything when the phones initially register?

Hi Leejor,
I don't be believe we use SBCs (sorry this server was setup by the last IT guy), I've checked under SIP Trunks and cannot see any SBCs there. Is there anywhere else to confirm this?

With regards to the activity log, are you referring to the event logs at the bottom of the Dashboard page? If so, yes I've had a look there and cannot see anything obvious. I am still pretty new to 3CX, is there any message in particular relating to this issue that I should look out for?

It certainly feels like a firewall issue but I cannot seem to put my finger on it.

Thank you

 

[leejor]

Not the Event Log, there is an Activity Log that shows details of all calls passing through the PBX, the detail level can be changed as needed.

 

[SONIQ]

Ahh I see. Ok, so the activity logs shows the below, does this look correct? Should be "<sip:[email protected]:0>"? 730 is the correct extension.

10/30/2020 6:02:21 PM - [CM503003]: Call(C:179): Call to <sip:[email protected]:0> has failed; Cause: 487 Request Terminated/INVITE from 127.0.0.1:5483

 

[leejor]

That shows the failed call attempt to ext 730. The IP 127.0.0.1, would seem to indicate that 3CX does not know the actual IP of the device, it is un-registered.