Phone losing Dial tone

[jake.peters]

Hi,

We have an issue where the phones lose dial tone and can not hear anyone on the other side of the phone, and when rebooting the phone it shows SIP register failed and one phone shows timeout error, we then have to reboot the router and the switch and it brought all the 4 phones back online, however we do not suspect it to be the switch as there were 2 other phones on the connection and they were fine. They are using a Draytek router

 

[leejor]

If possible, swap out the router. That's about the only way you can be certain that it is not causing the issue. It wouldn't be the first time that a piece of hardware that "shouldn't do that", did.

 

[JohnS_3CX]

Do you have an 3CX SBC installed at the site?

If not, then this is the first step you need to take.
https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

 

[jake.peters]

They have no SBC installed on-site
They have 2 Fanvil X4U-v2, 2 Fanvil X4U and 2 Fanvil X4 if this helps

 

[JohnS_3CX]

Then you already have 2 SBCs available at your disposal in the form of router phones.

Make the 2x Fanvil X4U-V2 into router phones, and spread the remaining 4 phones, 2 behind each SBC.
https://www.3cx.com/sip-phones/fanvil-x3-x5/#:~:text=Router phones: X4U-V2

 

[jake.peters]

Okay, we have set that up, will just monitor and Ill update if that has fixed the issue

Appreciate the help

 

[JohnS_3CX]

Great news, let us know how it goes!

In case you face the same issue, you can look at the Voice & Chat page and check if the X4U-V2 SBCs are green.