Solved Fanvil X5U not provisioning for Hot Desking

[KonnectCraft]

Adding few more Fanvil XU phones to existing setup. PBX hosted on AWS, Firewall checker passes, no issues with existing phones or sites.

High Availability SBC Cluster on site.

Steps taken:
1. Upgraded the phone to the latest available firmware
2. Added the new Hot Desking phone with the Device MAC Address and the SBC address
3. The new phones are detected on the phones page but clicking on 'Assign Extension' does not do anything.

So far, tried rebooted the SBC Cluster, rebooting the PBX, turning off On Premises Firewall.

Am I missing anything here?

 

[JohnS_3CX]

Hello,

Are the phones inside a network / VLAN that allows them to access the internet?

Have you upgraded the X5U firmware to v2.4.12 specifically?

 

[KonnectCraft]

Hello,

Yes, they are able to access internet from that VLAN. Phones are visible on the 'Phones' section on PBX. Also, SBC can reach the PBX.

Yes, the firmware is on 2.4.2 as well.

Thanks,
John

 

[JohnS_3CX]

Please send me a private message with the key of this machine so that I can quickly check a couple of things

 

[KonnectCraft]

Hello,

Yes, they are able to access internet from that VLAN. Phones are visible on the 'Phones' section on PBX. Also, SBC can reach the PBX.

Yes, the firmware is on 2.4.2 as well.

Thanks,
John

Sorry I mean 2.4.12

 

[KonnectCraft]

Please send me a private message with the key of this machine so that I can quickly check a couple of things

I just did.

 

[JohnS_3CX]

Ok try the following please

1. Delete the MAC from your extension.
2. Delete the PnP entry from the phones page.
3. Factory reset the phone.
4. Create a Brand new extension and do not edit anything, not even the name.
5. Try to assign the X5U to this new extension and tell me if it worked.

 

[KonnectCraft]

Same result. It does not seem to be doing anything.

 

[JohnS_3CX]

If you delete the PnP entry, and reset the phone, does it appear again on the phones page?

 

[KonnectCraft]

Yes it did.

 

[JohnS_3CX]

Ok in this case, you need to log into the web ui of the X5U, start a packet capture, and then try to provision it from your management console.

Give it a minute or so to "fail" then stop the capture and save it. If you open it in wireshark you should see the following

1. NOTIFY message from SBC IP going to Phone IP (containing your FQDN)
2. 200 OK message from Phone IP to SBC IP
3. Phone will perform DNS request for your 3CX FQDN
4. If it gets a response, it will try to establish TLS connection to the IP of your FQDN

If the TLS connection succeeds it should download the config file. If any of the above steps do not happen for any reason, or you get a wrong DNS reply, then it will explain why the failure occurs.

 

[KonnectCraft]

Hello John,

After checking all the capture logs from the phone and network logs, I was able to fix the issue. Thank you for all your help.

 

[JohnS_3CX]

Glad to hear it was resolved! If you like, you can share what issue you found and how you fixed it if you think it can also help others

 

[KonnectCraft]

The on-site firewall was blocking the incoming packets to SBCs. I whitelisted the IP of the PBX on the firewall to prevent this from happening again.

 

[JohnS_3CX]

Excellent, thanks for updating the thread!