How make cable PoE for Cisco Phones

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Nov 6th, 2007
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I get in touch with you to make an inquiry. I have a telephone Cisco 7940, I want to use through a single Ethernet cable and power PoE. I connect the phone to a switch PoE but I do not know how is the braided cable Cat.5 before you can use them with PoE.

Please inform me how could I make the cable.


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a.cruea1980 Tue, 11/06/2007 - 04:23
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Any standard, straight through cable should allow for PoE operation.

If your phone is not powering on when you plug in an ethernet cable, make sure your switch is set to provide PoE on that particular port.

culturajoven Fri, 11/09/2007 - 10:21
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I bought a switch NETGEAR ® PROSAFE ™ 8 Port FS108P (with POE), which supports the protocol IEEE

I have my phone connected to Cisco 7940 with a cable network, but it does not work, will not ignite.

Somebody knows whether the FS108P is compatible with Cisco 7900 series phones?

Someone could tell me if a crossover cable could operate?

Best regards,


pstebner1 Fri, 11/09/2007 - 11:36
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The 7940 is not compatible with the standard. It only works with Cisco's proprietary implementation of PoE.

I'm sure that you could change the pinout on a CAT5 to make it work, but I'm not sure which pairs are used. A crossover cable will not work, as that only swaps 1,2 with 3 and 6.



EDIT: I just found this:

So it looks like if you swap 4,5 with 7,8 it would work, but I claim no responsiblity if it blows up!


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