Yealink Phones Fail to Provision after a Network Outage

[ryuzaki504]

Hey guys,

Over the past few months I've been seeing a pattern at about 5 out of my 90 satellite offices where the Yealink phones failed to provision or communicate outside the LAN after a network outage. In rare cases this happens overnight without any network outages. The phones will require a reboot to provision and check back in with the PBX. The phones are configured for DHCP like the rest of our satellite offices that experience no issues. Lastly, the phones have the latest firmware and the PBX is running the latest version. Any ideas on a fix or what might be causing this to happen?

 

[ryuzaki504]

I went ahead and configured several phones to STUN and that seems to prevent this from happening, but I'd like to avoid configuring every phone to STUN if all possible.

 

[SteveITS]

Define "network outage"? A switch dies?

Since you mentioned DHCP, do the phones have a DHCP address when this happens? (is the lease time short perhaps)

Does restarting the SBC not help?

 

[ryuzaki504]

Network outage = ISP service outage or power outage.

I checked this morning and phones are still being handed IP's from DHCP, but are not reachable when trying to access the GUI via their IP's until a reboot happens.

We don't use SBC's in our environment. Traffic goes out of the firewall and communicates directly with the PBX.

 

[ryuzaki504]

Define "network outage"? A switch dies?

Since you mentioned DHCP, do the phones have a DHCP address when this happens? (is the lease time short perhaps)

Does restarting the SBC not help?

See my previous reply. Also, something to note. This morning those affected offices all had their phone provisioning/service drop without an outage. It's like they just randomly decided to stop communicating with the PBX, and when I looked in 3CX all phones were red/down and un-pingable. What's weird is that they still had IP assigned to them though.

 

[SweetAction]

So you can't even hit the phone WebUI until it reboots after the outage?

This points to networking being the issue (not 3CX specific) - specifically if traffic isn't being handled/answered by the phone at all, I would start with packet captures to find out why. Is the phone getting, is the phone sending, etc.

 

[ryuzaki504]

Thanks for the replies, guys. I'll run a packet capture and check the firewall configs at those offices and stare at it until something sticks out. What makes it tricky is we typically standardize our configs, so it's weird that it's only happening at 5 or so locations out of the 90 that we have.