POE CLASS 4 for 9951 phones

Unanswered Question
Jan 9th, 2010

Hi im roger

i already bought 3 9951 phones and a 7975 for the office but i wont the power cube 4

i read this https://supportforums.cisco.com/message/1172505#1172505 was good but i didnt find for class 4

and this http://en.wikipedia.org/wiki/Power_over_Ethernet  its more explaining

So the question is class 4 its the same for POE+?

and which small or medium switch i can get?

and if can i use the 2800 or 2900 routers with AC-IP?


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Overall Rating: 4 (4 ratings)
Leo Laohoo Sat, 01/09/2010 - 13:38

I the 9951 requires up to 20.0w of power.  The only switch models that can do this is the 3560E and 3750E (with the correct IOS, of course). The 2800 will not be sufficient but I'm not sure about the 2900.

royescobar Sun, 01/10/2010 - 14:14

Thanks rob and leo

nice thread rob

So in advance resume from the rob link


4) Power is listed as 802.3af and 802.3at support.  Are there any limitations when using 802.3af instead of 802.3at? I am guessing the USB ports may require the Class 4 PoE?

If using 802.3af power and wish to take advantage of the Cisco Unified IP Color Key Expansion Module for expansion of line/feature appearances, then power cube 4 power supply (supporting the IP Phone) is required to support the module or modules (actual number of modules is phone model dependent). Also note that 802.3af supports up to 15.4W of power to a given device and the classification of the power consumption is static and cannot be renegotiated later on. The AT specification allows power consumption up to 25W PLUS the ability to change power consumption after the initial classification.

Kirk McNeill

Collaboration Solutions Marketing

Cisco Systems

It looks like the 9900 series are class 3 POE even a catalyst express 500 can power on the phone according from cisco


another important question

2. Regarding the 802.3af and 802.3at support on 9900 IP phone, does this means 9971 with camera will be able to be supported by a 802.3af switch port as well?

Yes, the 9900 Series endpoints can support the Cisco Unified Video Camera, upon its availability, with Class 3 IEEE 802.3af. If one wants to add the IP Color Key Expansion Module, that would require purchase of the Power Cube 4 for local powering of both the Phone and Key Expansion Module.

Kirk McNeill

Collaboration Solutions Marketing

Cisco Systems

a good news so the 9900 series its a regular poe phone and can use full features like full color, bluetooth, and video camera with poe class 3


3.What about support for the 9971/51 with UC500 and CME environments?

View for UC-500 is targeting support mid-year 2010.

View for Communications Manager Express with Integrated Services Router (ISR) is roadmap item for CY 2H 2010.


this link its nice to those who want to know more about 9900 phone series


this tool is a calc for POE in cisco switch family


So i already order the phones to test them to update the thread



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