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New Member

IP phones reboot randomly - 7960

Running IP phones with inline power (6.3v from the switchports i believe).

It's only the 7960 phones which seem to reboot at random.

Recent change to Callmanager v3.3 settings was to set 'MaxLoginTime' for Extension Mobility to 'False' - thus allowing Ext Mob users to remain logged into an IP phone for eternity (theoretically :) Issues with the reboots seem to have happened after this (if i am to believe the users!)

The local switch shows a few ports with tx and rx errors, and some runts. However, several phones have been reported as having 'rebooted' yet only two ports have these tx/rx errors.

Cisco support site lists some vulnerabilities for IP phones when XML is pushed to them/hackers causing DOS attacks etc. Given that all our kit is behind firewalls (and we are on a later version of CallManager that the DOS issue apparently doesnt affect) then i'm not so sure the DOS issue is relevant.

Any thoughts...? Seems a bit odd and random - the worst type of possible network/phone issue!! lol

Hall of Fame Super Gold

Re: IP phones reboot randomly - 7960


Be reassured the phones are rebooting because of bugs and not hackers.

What FW (load) are you running? Please upgrade to latest 8.0(5) and try again.

Hope this helps, please rate post if it does!


Re: IP phones reboot randomly - 7960

I would go to the phones menu -> Setting->status-> and check status and Networkstatistic after or during the Phone is rebooting. Second thing is to activate traces on CCM (SDI,SDL) and see what s causing this problem.

New Member

Re: IP phones reboot randomly - 7960

Thanks for the suggestions chaps. I am running down the inline power route first - giving some IP phones Cisco Power Cubes to provide power to see if the fault lies at a switch level first.

The switch reports that power is only running at about 60% saturation, but this seems like the best first step.

Beyond this, i suspect CCM debugs will need to be run to see if it is the XML uploads to the phones that is causing issues.

Hall of Fame Super Gold

Re: IP phones reboot randomly - 7960

Hi, no matter the features used, the phones should never crash, so once you have the latest image, if they keep crashing, it's matter for the TAC.

Re: IP phones reboot randomly - 7960

If you have a POE switch, try using a power supply with the 7960 that is having an issue just to see that its not a power issue. I have also had an issue with CAT cables being the issue. (bad patch cables, etc) The phone will try and negociate a switch port speed (10/100) when the port is set to Auto and phone on auto. IF the there is confussion between with the switch or lost packets, the switch may try and re-negociate a connection with the phone port, hence the POE drops, reboots the phone and reconnects.

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