Enhanced PoE on 3750E/3560E - on how many ports?

Answered Question

On a 48port variant of the above switches, how many ports will be able to deliver full power to our AP-1250's ?

I have this problem too.
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Correct Answer by andrew.butterworth about 8 years 3 months ago

In the 12.2(44)SE release notes for the 3750-E/3560-E it states that all 10/100/1000 PoE ports can provide Enhanced PoE up to 20-Watts per port. I assume like earlier 3560/3750's its just a simple maths calculation -

48-port 3750-E/4560-E with single PSU can provide up to 370-watts so you would get a maximum of 18 ports providing 20-Watts. With the dual PSU versions they can provide up to 740-Watts so you would get 36 ports providing 20-Watts.

There is a presentation slide here that states with a 24-port 3750-E/3560-E you will be able to power 20 1250's and a 48-port one will power up to 40. Only the 48-port 3750-E/3560-E's can have dual PSU's (Full Power) so this ties in. If you work the maths out it means each AP actually requests and gets 18.4-Watts:

http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps6973/80211n_Cisco_Intel_Roadshow_Final_01_16_08.pdf

HTH

Andy

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Mark Yeates Wed, 09/03/2008 - 09:10

Ole,

The following switch models will be able to provide provide 15.4W PoE power to all 48 ports on your switch.

3560E-48PD-F

3750E-48PD-F

HTH,

Mark

Thank you for the answer, but i'm talking about enhanced PoE. To power up the Cisco 1250 ap's via ethernet, i need approx 17-18 watts pr port. Enhanced PoE does support this on these switches, but i cant find out if it will manage to deliver on all 48 ports at the same time.

Anyone who can point me in the right direction on this?

Correct Answer
andrew.butterworth Wed, 09/03/2008 - 23:19

In the 12.2(44)SE release notes for the 3750-E/3560-E it states that all 10/100/1000 PoE ports can provide Enhanced PoE up to 20-Watts per port. I assume like earlier 3560/3750's its just a simple maths calculation -

48-port 3750-E/4560-E with single PSU can provide up to 370-watts so you would get a maximum of 18 ports providing 20-Watts. With the dual PSU versions they can provide up to 740-Watts so you would get 36 ports providing 20-Watts.

There is a presentation slide here that states with a 24-port 3750-E/3560-E you will be able to power 20 1250's and a 48-port one will power up to 40. Only the 48-port 3750-E/3560-E's can have dual PSU's (Full Power) so this ties in. If you work the maths out it means each AP actually requests and gets 18.4-Watts:

http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps6973/80211n_Cisco_Intel_Roadshow_Final_01_16_08.pdf

HTH

Andy

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