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Desktop Phone, assigned to user, toggles between online and offline


We have reviewed the firewall settings recommended by Zoom and don't see any issues.

We're using Yealink T54W phones. Device firmware is

If the phone shows as offline (both on the display and in the Zoom Phone admin console), when you re-provision it through the on-screen settings, it comes back online.

Sometimes the phone will remain for hours online, then go offline.


Community Champion | Zoom Partner
Community Champion | Zoom Partner

hi rpearson,


intermittent issues are hard to trouble shoot.  might be a network issue or could be a yealink issue.


are you using wifi or wired connection?


you might try plugging the phone into another ethernet connection and see if that stops the issue.


i would open a ticket with yealink.


Did my response answer your question? If so, please don't forget to mark the reply as an accepted solution.


thanks,  eliot




Thank you for the suggestions Eliot.

The error is 'User unregistered', and I have found a few other reports of this issue with the Yealink T54W phone. There are a couple of network settings that might affect this, but so far I have whitelisted the recommended Yealink URLs in our firewall and updated the firmware.