UCM6204 Phones quit working till reboot


i have a ucm6204 and i’ve been noticing that every 7 days the phones stop working. i can log into the ucm and the memory is at 35% once i reboot it everything goes back to normal! is there any fix for this? it has been happening for the last couple months, nothing has been changed on the system. Is there a way to set up auto restart?


Hello Phil,

I’ve never personally run into this issue but, the few times I’ve seen other people bring this up. They had not protected the UCM correctly and, it seemed anyway, they were probably experiencing some hacking attempt.

This is all probably old info but…

  1. Make sure the UCM is behind a firewall. Many people think the UCM has a built in firewall, it’s ok on the network edge but, it is not. It does not have the horse power to keep itself safe.
  2. Ensure you’re using proper port forwarding. Use ACL settings in your firewall. If your firewall does not support ACL change the default port from 5060 to some random port over 50000 to prevent (not a guarantee to eliminate) port scanning and login attempts. If you’re firewall is not a quality firewall, consider upgrading.

Again, I realize you’re messaging from “A Network Company” in Ohio so, these are probably already taken care of.

This is not the only answer, there are certainly other people who’ve seen other issues cause this but, I hope it’s a productive place to start.



What firmware version are the phones running? We had similar lockup issues on some of the later versions of 1.0.9.xxx.


yes all the ports are forwarded and the firewall is configured… to me it seems like once it hits a certain memory percentage it starts getting screwy!


that i have not checked! last i knew it was on the most updated firmware! next time i am at the site i will check the firmware and update as necessary!


The phones are on the latest firmware and everything seemed fine for the past couple months and it just started happening again!


Check UCM Dashboard

Any space usage is 100 % ?