3CX on Azure - Unregistered phones

[adaraujo]

Hello everyone,

I have a 3CX PBX hosted on Azure and configured as local using a VPN between Azure and FortiGate. The system is configured in four locations with 3 types of phones, Fanvil x3U, Fanvil x4U and Polycom VVX 411.

The problem is that suddenly the phones start being unregistered, not all locations at the same time. I Always check the VPN, and it is working (I can ping the 3CX server), but even pinging it seems the phones cannot register. The weird thing is that sometimes only a few phones stop working in the store, and all of them are connected to the same switch.

I try to reboot the phones, reprovision, reset the VPN, and nothing works besides rebooting the Switch.

I tried different switches, but the problem still happens. I have tested on DGS-1210-28P and JetStream 52-Port Gigabit switches (both POE).

Does anyone has the same problem?

 

[Alejandro_3CX]

Hi @adaraujo, I wonder if you try to configure one of those Fanvil X4U as router phone and another phone as normal behind the router phone do you also have the same issue?

With this test check that phones are using the correct firmware, default template and that the firewall checker pass successfully.

 

[adaraujo]

The X4U has FW: 2.4.12
The X4U-V2 has FW: 2.12.15.6

By router phone, do you mean SBC?

I have one phone configured as SBC.



That is actualy the test I am doing.

 

[Alejandro_3CX]

By router phone, do you mean SBC?

yes, router phone are the devices that has the 3cx sbc inbuilt, for example the fanvil x4U can be used as router phone. Then you can provisioning another phone as normal using the router phone as sbc.

With this test check if you have the same issue or not.

 

[adaraujo]

It has been working over SBC since last Thursday.
I will keep monitoring and advise here.

How many phones can I have over one router phone?

 

[Alejandro_3CX]

You can have 10 Normal IP phones behind the router phone.

 

[adaraujo]

Ok, thank you for the help.

 

[Alejandro_3CX]

You are welcome, have a great week ahead!

 

[adaraujo]

Update:
Configured some extensions as SBC, and they worked for a week and stopped working.
The problem persists.

 

[Alejandro_3CX]

Hi @adaraujo I wonder if you have monitored the connection on the tunnel port 5090 TCP and see if there are any retransmissions, etc, this will indicate the packets are being lost between the networks. You can start monitoring and debugging from there running some T-sharks on the pbx server and capturing packets on the router phone.

Also check if the internet connection is stable or not in that remote location, you may leave a ping running the whole day for example ping -t google.com > C:\OutputPing.txt and see if there was a disconnection or not.

 

[adaraujo]

Hi @Alejandro_3CX, I did not monitor, but I wonder why it wouldn't connect or register the phones again after the connection is supposed up again. I have to reboot all phones to make it work and sometimes change the provisioning link to something else and put it back again.

By the way, the Router phones do not stop working, only the phones connecting to the router. (I tested 9 phones)
Another thing is that not all phones connected to the VPN stop working, it can be partially affected or just a few stop working and usually once a week.

Note: I have other VPNs connecting to other systems and they do not stop working.
.

 

[Alejandro_3CX]

why it wouldn't connect or register the phones again after the connection is supposed up again

Each device has a sip time registration, by default it is 120 seconds, the device will attempt to refresh the registration just some seconds before reaching that time. If the phone is not registered it will try to send a new register message, then if there is no response it will try to send another one after a period of time and so on, this time is going to be increasing meanwhile the device has no response... So if disruptions are taking longer then that will explain why rebooting the device will work.

only the phones connecting to the router. (I tested 9 phones)

Please validate that the phones are supported devices, using the recommended firmware and template.

Also run the firewall checker and check it pass successfully

If you keep having the same issue after all, then please kindly can ask your 3CX Partner to open a support ticket to gather some logs and captures about the issue.

 

[JohnS_3CX]

Just to add to what my colleague said, please note that we would recommend to add a DHCP reservation for the router phone.