What is the actually power usage for a 9971, 8941 and 8961 phones

Unanswered Question
Mar 2nd, 2011

     We are looking at deploying many Cisco 9971 IP phones. On the specs for the 9971 phone it says it uses class 3 power, but this usually reduced when CDP is enabled. Does anyone know what the actually power usage (xx.x watts) of a 9971 IP phone? We might also need side cars for additional functions too. Does anyone also know what the power usage might be for class 4 power (Cisco 9971 IP phone with side car)? I will also need the same information for the Cisco 8941 phone too.

Thank you,


I have this problem too.
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jeff.sadowski_2 Thu, 03/03/2011 - 04:48

     Thank you for your reply on the power usage for the Cisco phone models. I have also done the same power conversion v*a=w. What I want is to confirm what the switch actually sees for the power usage. If you or someone has these model phones within their network and can do a sh inline power to confirm the power usage.If you or someone also has one side card attached to these phone models that can also do a sh inline power too. This confirmation would be great information. We might need to deploy most of these model on Cisco 3750 V2 48 port switches and I want to make extra sure how many phones can we attach for capacity management. The current cisco power calculator does not have this make and model available for PoE devices and does not have the option for sidecars. If you don't have all these models that is Ok, as long as I get some information from one person and than some more from another.

Volodymyr Morskyy Thu, 03/03/2011 - 05:03

or show cdp en SEPXXXXXXXXXXXX can be run on a switch but with alerady connected ip phone(example for 7960):


Entry address(es):

  IP address: xxx.xxx.xxx.xxx

Platform: Cisco IP Phone 7960,  Capabilities: Host Phone

Interface: FastEthernetX/X/X,  Port ID (outgoing port): Port 1

Holdtime : 170 sec

Version :


advertisement version: 2

Duplex: full

Power drawn: 6.300 Watts

Management address(es):

PS: Sorry, don't have these phones in my environment.

jeff.sadowski_2 Thu, 03/03/2011 - 05:56

     Thank you for your help with another way to also should the power usage of the Cisco phones. Like you I currently don't have these models within our network, but would like to possibly purchase them. I hope that someone in the Cisco Support Community might have these models and can confirm the power usage they see on their switches. I know these are newer phone models and more of the high end, but I think someone might already have these models and can help confirm the power loads on the their switches.

Thank you,


jeff.sadowski_2 Thu, 03/03/2011 - 06:11

     If possible if you could do the "sh cdp en SEP*" would be perferred over the use of "sh power inline" for anyone that has these phone models. It does give more detail power loads. If you don't want to run this CDP command, because of the additional information, please only forward the model and power load.

Thank you,


Kevin-John Beasley Fri, 06/01/2012 - 06:07

Hi Jeff,

Here's a partial answer at least:

#sh cdp en SEP0008308B9054
Device ID: SEP0008308B9054
Entry address(es):
  IP address: ******************
Platform: Cisco IP Phone 9971,  Capabilities: Host Phone
Interface: FastEthernet2/0/8,  Port ID (outgoing port): Port 1
Holdtime : 151 sec

Version :

advertisement version: 2
Duplex: full
Power drawn: 14.389 Watts
Power request id: 21653, Power management id: 12
Power request levels are:14389 0 0 0 0
Management address(es):

#sh cdp en SEPA45630BAC1A0
Device ID: SEPA45630BAC1A0
Entry address(es):
  IP address: ***********************

Platform: Cisco IP Phone 8961,  Capabilities: Host Phone
Interface: FastEthernet2/0/19,  Port ID (outgoing port): Port 1
Holdtime : 166 sec

Version :

advertisement version: 2
Duplex: full
Power drawn: 15.400 Watts
Power request id: 41155, Power management id: 4
Power request levels are:15400 0 0 0 0
Management address(es):

I think the 8961 has a expansion module connected which explains the higher power usage. I can probably disconnect it some time and get you a nominal power reading. Don't have a 8941 to test so can't report on that one.

leoluzana Thu, 08/22/2013 - 02:26

hi Kevin,

Is 8961 has indeed an expansion module (or KEM) attached to it?

i wanted to know since we might not be buying an added power cord/cube, if that is the case.

(we will only need to buy 1 KEM on our expansion project)

per cisco standard, At least one KEM can be powered up if the Cisco Unified IP Phone 8961, 9951, and 9971 uses AT PoE.

However, that 3750 switch is on a 802.3AF-PoE standard which provides up to 15.4 W of DC power.

Your confirmation will help a lot.


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