PoE Phone Issue

Unanswered Question
Mar 24th, 2009

One of our locations temporarily lost power yesterday and a few phones lost power even though the switch is on a UPS. Other phones on the same switch stayed on with no problems. Has anyone ever experienced an issue like this and have any advice?


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cedricm73 Tue, 03/24/2009 - 07:01

Hi, does your Switch have 2 power input and does the 2 power input are connected to a UPS. What could happen is that if one of your power input was on Direct current and the other one on UPS, when the power went down, the switch doesn't have enough power to dispatch to all phone and start to cut phone starting from the end of the switch or from the last blade. check if all the phone which have lost power was on ports which are closed on the switch. thay may be helpful to understand where is the issue.

hippieboy9 Tue, 03/24/2009 - 07:22

The switch only has 1 AC power input and it is plugged into the UPS. It appears there is a DC input but it is not used. The PoE utilization on the switch is only 28%. The config is the same for all of the ports.

kumar3880 Tue, 03/24/2009 - 21:58


Kindly let me know the mnodel of the switch that is been used for the PoE.Also please do check the total power consumed by the ip phones in the Switch.

As if it had utilised maximum power from the switch,connecting more ip phones will not have sufficient power.

Also do test if the ip phones which no power is working when connected to other ports(which are in use)



hippieboy9 Wed, 03/25/2009 - 08:46

The switch is a 3560. The PoE utilization on the switch is only 28%. There are only a few things plugged into the UPS which include the router, switch, and a domain controller. This is happening at a remote site in another state so I will have to wait until the next time I am on-site to try switching the ports for the phones with no power.



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