Time-of-day PoE power down of IP phones

Unanswered Question
Apr 16th, 2009

Hi all,

We are deploying some 6513's as new Access Layer switches, and it appears that there is a newer 'green' IOS code (Cisco Energy Wise feature set) that we could deploy that has some rudimentary time-of-day PoE commands that will allow us to have IP phones powered down at night, for example.

Has anyone used this newer code? Does it allow the phones to be in a 'standby' mode of some sort, so a user can lift the handset and the phone re-awakes? Or will this completely power IP phones off...?

Im worried that if we have support staff working late fixing a problem, their phones will power down if we deploy the PoE time-of-day power controls lol

Any ideas how well this PoE power control works?


I have this problem too.
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htluo Thu, 04/16/2009 - 07:01

If the power is shut down from the switch side, the user won't be able to 'wake it up' from IP phone.

On some model of IP phones (such as 7965, 7970, etc.), you may configure Time-of-Day on CUCM > Device > Phones. So the phone can be in standby mode. In that mode, it can be wake up by user.



iptuser55 Thu, 04/16/2009 - 08:01

I thought it powered them off completely via a commend in the IOS. We have a meeting with Cisco regarding this, a good idea but maybe 12 months too early the sleep mode is still some way off yet if I remember the talk. You had to configure some phones on the floor not to be turned off for emergency calls- Lets hope the fire you are reporting is near the powered on phone

Tommer Catlin Thu, 04/16/2009 - 07:46

adding to Michael's response..... while it's great you are trying to conserve energy, there may be a liability issue with having the phone turned off. If someone is in the office and needs to dial 911 and the phone is off, then what? I'd check with your legal eagles to see if this would be an issue.

The standby mode at least turns the screen off at defined days and times. This drops your power consumption a ton. Half the power the phone uses is probably the color screens these days. (you can run a test on the POE output when the phone is idled and screen in standby, compared to screen on, etc.

andy_vvc2 Thu, 04/16/2009 - 08:33

Thanks for the updates all ! Points all-round there.

I hadn't actually stopped to consider the legal/safety ramifications of having phones powered down. If there is no 'sleep' mode available yet on the 7960's that we predominantly use, then we cant really deploy the PoE energy saving idea.

Our 7970 phones 'sleep' (screen goes blank) after about 60 mins of inactivity. However, i haven't compared the power that a 'sleeping' phone and an awake phone pull from the PoE switch. Does it actually drop....or does the device always pull the normal wattage?

Cheers once again! Some very useful comments from you all :o)

rob.huffman Thu, 04/16/2009 - 08:55

Hey Andy,

I thought that this was an excellent question, especially given the current co$ts associated with Energy. I have scoured everywhere that I could think of trying to find a defined number and this seems to be the best:(

Here are the current references from Cisco;

Low-power modes on IP phones: Cisco Unified Communications Manager provides a central command that can darken the displays on all the IP phones connected to a network at a given time after business hours. This can save up to **25 percent of a phone's typical energy consumption.



Hope this helps!


Leo Laohoo Thu, 04/16/2009 - 21:40

There's suppose to be a forum regarding EnergyWise (http://forums.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Network%20Infrastructure&topic=LAN%2C%20Switching%20and%20Routing&topicID=.ee71a04&fromOutline=&CommCmd=MB%3Fcmd%3Ddisplay_location%26location%3D.2cd25609). Take note I said "suppose to be" because no one from Cisco has been answering a number of the questions. :)

When EnergyWise is enabled on the selected switches (2960, 2975, 3560/3560-E, 3750/3750-E), the IP Phones, for example, won't wake up. This is, in my opinion, a flaw. So far, Cisco and Microsoft have not yet come up with a solution of waking up a PC when someone wants to work when EnergyWise turns off or standbys the port.

By the way, latest IOS with EnergyWise is 12.2(50)SE1.

iptuser55 Fri, 04/17/2009 - 01:17

Following on , we had a meeting with a guy regarding Energywise adn Cisco and it seemed they were "fishing" for information, concerns telephony support people may have, It may be easier from a Server, PC point of view but from voice the legal issues were greater. He admited it may be 12-18 months away for a "working IOS" to be avalable which will be suitable mostly based upon the 999, 112, 911 issues . Maybe for voice they have came to the market too early and jumped on the green wagon

Brian McPhillips Tue, 09/13/2011 - 06:25

Hi Guys, im currently running a small test on energywise and lms 4.0 to roll it out. I have been looking for info on this for a while and the phones supported. is there any information on the latest phones which support the wake on lan? or will there be firmware upgrades for older phones? Currently we have 7961s, 7941s and 7911s.

Also in LMS can you remove a policy or update it. seems like it just keeps adding the policies on top of each other!

iptuser55 Tue, 09/13/2011 - 07:25

On CUCM 8.X something you can have TOD power down on 69xx version phones which I think can be overridden when a users picks up as in a 999 - 911 call for other phones I do not think you can override this at least on TOD CUCM 8.X

hope it helps


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