T58W-Pro Hotdesk - mysterious sudden reboots

[perfect-touch]

We have four Yealink T58W-Pro deskphones in the system. They are configured as hotdesk phones and, although they have a custom template, the template has not been updated for several months.

They have been on the 3cx firmware level 150.87.0.20 for some time now with no issues.

They are operating as router phones, using themselves as routers - the 3cx PBX is hosted offsite. There is a separate SBC running onsite which is the one used for all non-router devices - none of these router-phones are configured as the SBC endpoint for any other devices.

As of yesterday, they have started rebooting several times a day - and I am at a loss to understand why.

Any pointers where I should look - hopefully other than reverting one of the to a standard template? Given that neither the firmware not the template has changed, that feels like a large, backward step.

Finally, the only other hotdesk phone, a Yealink T58 does NOT seem to be having the same issue.... as far as I can see

 

[TheodorosG_3CX]

Ensure first that you are using the default template in order to verify if this is the reason.

 

[JohnS_3CX]

A very important detail you said is that this started yesterday. So what changed? the network conditions? The power delivery? The phonebooks grew too large suddenly?

Get rid of the custom template and reprovision one of them clean - you are troubleshooting with less unknowns then. Or leave one unprovisioned and see if it also reboots so you can eliminate provisioning altogether and focus on network and power delivery.

 

[perfect-touch]

OK was trying to avoid losing the customisation but feared this would be the initial answer.

2 deskphones powered PoE by different switches to the other two so "unlikely" to be a power-supply problem

No network changes at all and the T58 seems unaffected (uses the same template)

I will revert one of the phones to the standard template and see if it experiences less issues. Leaving one device unprovisioned is impractical during the working week, sadly.

The phonebook tends to be updated once a week - no updates have been made this week

 

[JohnS_3CX]

Don't rule out PoE just yet. It's unlikely, until its likely, if you know what I mean.

The other thing is network broadcast storms, they can bring phones down to their knees easily causing sluggishness, reboots, deregistrations.

I have also seen DHCP option 132 VLAN transmissions causing reboots as the phone "learns" the new VLAN config from your network and tries to apply it.

I would confirm both of the above if it was all fine and dandy until yesterday, clearly something did change.

 

[perfect-touch]

Don't rule out PoE just yet. It's unlikely, until its likely, if you know what I mean.

 

[perfect-touch]

So, just to provide an update - I'd say the problem is "plugged" rather than "fixed"

Given the devices that were rebooting and those that weren't I deleted hotdesk phones that had been provisioned as router phones and reprovisioned them against the site SBC (still using the same custom template) and the rebooting has stopped - at least for the last four days. Just for info, none of the router phones were providing SBC functionality for any other SIP device on site, the non-hotdesk phones all use the site's software SBC.

So, I still haven't got to the bottom of the problem - and I suspect it must be network-related but (for now) the pressure is off. I may look at creating a two-node HA cluster for the SBC operation as it's suddenly become a little more critical to us.