Cisco IP phone 3905

[Nebbieaman]

Hi 

Having issue where our 3905 gets locked up after 2 hours and gets unregistered. They are plugged in to a C9300 switch . Only these phones are having issue. I have changed multiple firmware on them no luck. Even I got unreleased firmware from Cisco and that didn't help. Cisco tac is still looking into the issue but can't figure it out yet. The only new thing is the switch. The phones used to work fine but after replacement of the switch to c9300 the issue came up. The switch is on 16.6.5 version. Has anyone faced this issue?

[Leo Laohoo]

Upgrade the firmware of the switch to 16.6.6 first.
Next, is the phone getting a valid IP address?

[Nebbieaman]

Hi Leo

Thanks for replying. Ok I'll upgrade the switch. Though the switch is just passing packets and nothing else. Yes they are getting valid IP address. They get register and work fine until few hours and they lock up and get unregistered.

[Leo Laohoo]

If the phones are getting IP address, put the IP address into a browser.
There are log and core dump files that can be downloaded and analyzed.