Extensions not re-registering

[SDI-SH]

We have a 3CX Windows PBX at a data center with about 15 remote sites. If a remote site's internet goes down, the extensions loses its registration. When the internet comes back up, the extensions do not register back. We would have to change the IP on the phones in order for the extension to register again. Does anyone know a better method than to change the IPs on the phones to register the extensions after they go offline?

Phones are Yealink SIP T19P E2 and some Polycoms.

 

[leejor]

The configuration file should have the sets re-registering within 30 minutes of the last registration, unless that time was set to a lower value. That was/is the default time that 3CX required each device to "check in" (re-register). There should be additional settings as to how long, or how many attempts are made if re-registration fails. These settings may require tweaking.

When the Internet goes down, unless a call attempt is made, the sets probably have no idea that connectivity is lost as the local LAN is still active. You could lower the re-registration time, to say 5 minutes and see if that makes a difference.

 

[YiannisH_3CX]

Hello @SDI-SH

How are the sites connected to the 3CX server? Are the phones using STUN or SBC or is there a VPN in place? Have you checked the PBX blacklist to see it the IP's are blacklisted for some reason? Also have you tried rebooting the phones after the internet comes back? Phone registration expires after 120 seconds so phones try to re-register after 60 seconds.

 

[SDI-SH]

Thanks leejor, I'll look into modifying the configuration files for the phones.

YiannisH_3CX, there's an IPSEC VPN to each of the remote locations going to the data center. The PBX blacklist does not show any IPs. We have tried rebooting the phones after the internet comes back up but the phones don't come back online. The phone would be offline for a few hours before we noticed that it's offline and after power-cycling the phones, they are still unable to re-register. Where can we modify the registration intervals?

 

[bell]

I'm having the same problem on VPN. I don't change the IP's anymore I just change from UDP to TCP and it registers right away (slightly quicker then changing IP's now). Then the next time it doesn't register after the internet goes down I change back to UDP and it will register strait away. But no amount of restarting will get them to register.