Looking for a Cisco POE adaptor

Answered Question
Aug 29th, 2007

Hi.

I need to get POE to a Cisco 3750 switch that is connected by optic fiber.

Anybody knows if there is any Csico product to do it?.

Thanks for advance.

I have this problem too.
0 votes
Correct Answer by rob.huffman about 9 years 3 months ago

Hi Andres,

I'm very sorry if I have misunderstood your question :(

Power can also be supplied locally using an optional AC to 48-VDC power adapter (CP-PWR-CUBE-3=)

http://www.cisco.com/en/US/products/hw/phones/ps379/products_data_sheet09186a00801739c0.html

Hope this helps! This sounds like your best option.

Rob

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4 (3 ratings)
Loading.
rob.huffman Wed, 08/29/2007 - 15:42

Hi Andres,

There are many ways to power devices if your 3750 does not have PoE capabilities. I'm not sure if your are looking at powering phones or AP's but here is some info for both;

Cisco Aironet Power Injectors

Cisco Aironet power injectors are used to supply in-line PoE power to the access points.

Non-Cisco Power Options

PowerDsine Midspan Products

Most Cisco Aironet access points use inline PoE from power injectors or Cisco powered EtherSwitches, but the Cisco Aironet 350, 1100, and 1200 series access points do not directly support IEEE 802.3af power sources. These access points were designed before the IEEE 802.3af power standard was ratified and must use third party products such as PowerDsine to support IEEE 802.3af power sources.

PowerDsine offers midspan power products that allow customers to deploy a combination of

IEEE 802.3af powered devices and non-IEEE 802.3af powered devices such as the Cisco Aironet 1120 and 1121 access points and the Cisco Aironet 350 and 1200 series access points.

From this good doc;

http://www.cisco.com/en/US/docs/wireless/technology/poe/technical/reference/Power.html#wp43156

Providing Power to the Cisco Unified IP Phone

http://www.cisco.com/en/US/products/hw/phones/ps379/products_administration_guide_chapter09186a0080670510.html#wp1063898

Hope this helps!

Rob

mirtenmous Thu, 08/30/2007 - 22:47

My 3750 have POE capabilities but is connected to another 3750 by optic fibber so POE capabilities of 3750 can't be used so I am lookin for a POE ethernet to connect a 7912 phone to it.

Does Cisco have this product?.

mirtenmous Sat, 09/01/2007 - 11:06

Thanks for your answer, it is just what I am asking

I am looking for a POE adaptor to replace AC adaptor and it is a surprise that Cisco doesn't sell it.

I think I must to buy it in another place. Any suggest?.

rob.huffman Sun, 09/02/2007 - 07:54

Hi Andres,

You are correct that Cisco does not sell such a product, they do have an Official partner "PowerDsine" that does;

PowerDsine 6000 Power over Ethernet Midspan Family

To power up to 24 7912 IP Phones use PowerDsine 6024 ACDC

http://www.powerdsine.com/Products/Midspan/PD_6000.asp

The 7912 does not support IEEE 802.3af power but rather Cisco Pre-Standard PoE (see Table 21-6), so you will need the "Splitter"

http://www.cisco.com/univercd/cc/td/doc/product/voice/c_callmg/4_2/srnd4_2/uc4_2/42endpts.htm#wp1043937

Note When using the PowerDsine adapter cable (prestandard passive splitter), PowerDsine recommends that this adapter cable is installed near the access point. The adapter cable (part number PD-PS-401/Cisco) is available through CDW. For additional information, refer to this URL:

http://www.cdw.com/shop/products/default.aspx?EDC=519479

So you can use this mid-span PoE adaptor in the wiring closet as you suggested and power a number of IP Phones in a much cleaner fashion.

Hope this helps!

Rob

rob.huffman Sun, 09/02/2007 - 16:33

Hi Andres,

Be careful with that Tech Note :) This same reference doc does show that the 7940 and 7960 do need the "splitter". These models are also supported by Cisco pre-standard power and not IEEE 802.3af like the 7912. My understanding was that all older Cisco phones like these (7912,7940 and 7960) would require the "splitter". Just make sure that you only try one phone at first just to be safe.

Q. What IP phone models support the Cisco pre-standard method of powered device detection?

A. These Cisco IP phones can accept Cisco pre-standard PoE from a card integrated with a Cisco Catalyst switch or a Catalyst in-line power patch panel:

7985G

7960G

7940G

7910G

7910G + SW

7912G

7905G

7902G

These phones can draw local power from a power cube (CP-PWR-CUBE-2=) in addition to a country or regionally specific power cord (CP-PWR-CORD-xx=).

Q. What IP phone models support the IEEE standard method of powered device detection?

A. These Cisco IP phones support IEEE 802.3af PoE:

7961G-GE

7971G-GE

7941G

7931G

7911G

7941G-GE

Note: These Cisco IP phones support both the Cisco pre-standard PoE and IEEE 802.3af PoE:

7970G

7961G

7906G

From this new doc;

Power over Ethernet (PoE) Power Requirements FAQ

http://www.cisco.com/en/US/products/hw/phones/ps379/products_qanda_item09186a00808996f3.shtml

Hope this helps and best of luck!

Rob

Actions

This Discussion