15.4 W PoE on all 48 ports possible with RPS?

[Justin Huffman]

Hello, I understand that most 48-port Cisco switch models that support PoE do so by providing 370W which allows for 24 ports to run at 15.4W or 48 at varing wattage provided the sum isn't above it's alloted 370W. (e.g. 12 @ 15.4, and 20 @ 7.7W for 32 "powered" ports).

Is it possible to use a compatible RPS to provide 15.4 W across all 48 ports simultaneously?

For example, WS-C3560G-48PS-S - 48 gig PoE ports, allows only 24 ports of 15.4W at one time. If I use an RPS 2300 with the 3560, will that provide more power for PoE or is it strictly for redundancy?

Thanks for your responses.

[paolo bevilacqua]

No, it is not possible.

You need to buy a switch with adequate PoE power for all the phones you need to connect.

[Justin Huffman]

Ok, so the only fixed-configuration switches that offer full 48-port PoE are of the -SF/-EF variety? (WS-C3560E-48PD-SF, for example)

[paolo bevilacqua]

You will find all the details for each switch model in the product data sheet.

[Justin Huffman]

Thanks, :-/ I have read the data sheets, but it is the data sheets that made me ask the question. The 3560 data sheet says:

"Taking advantage of Cisco Catalyst Intelligent Power Management, the 48-port PoE configurations can deliver the necessary power to support 24 ports at 15.4W, 48 ports at 7.7W, or any combination in between. Maximum power availability for a converged voice and data network is attainable when a Cisco Catalyst 3560 switch is combined with the Cisco RPS 2300 Redundant Power System..."

Source: http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps5528/product_data_sheet09186a00801f3d7d.html

This leads me to believe that if I use an RPS 2300 it will give me maxiumum power across all ports, but after hours I can't find anything that rates the switch power when connected to an RPS.

It's substantially cheaper to simply purchase an RPS 2300 to boost my PoE rather than buy a -SF or -EF switch or another -PS switch.

[paolo bevilacqua · Accepted solution]

Again, PoE power is not increased with using the RSP product.

Reading the complete sentence:

Maximum power availability for a converged voice and data network is attainable when a Cisco Catalyst 3560 switch is combined with the Cisco RPS 2300 Redundant Power System for transparent protection against internal power supply failures and an uninterruptible power supply (UPS) system to safeguard against power outages.

The word availability is used in the sense of "guaranteed continued disponibility", not "increased peak PoE power". Then is explained how one should use both an RSP and USP combined to achieve that.

[Justin Huffman]

Ohhh ok. Thank you very much, I understand now.

Sent from Cisco Technical Support iPhone App

[Leo Laohoo]

If I use an RPS 2300 with the 3560, will that provide more power for PoE or is it strictly for redundancy?

Hi Justin,

Just WHAT are you trying to do????

You have a 3560E, am I correct?  If this is so, WHY do you want to attach an RPS for?  This is wasting good money.

The 3560E can support DUAL POWER SUPPLY.  Let's say you want all 48-ports to support PoE, then get TWO units C3K-PWR-1150WAC.  Put one of the Power Supply in main power and the other in UPS.

Problem solved and done so with minimal expenses.

By the way, your "RPS" method is more expensive. 

[Justin Huffman]

I am trying to power 38 x 802.3af devices (phones, APs, IP cameras). 36 of these devices do pull a full 15.4W, 2 are only 10.2W.

I do not have a 3560E, as stated above I have a 3560G and was hoping to use an RPS to "unlock" additional PoE ports from the base 24. I can procure an RPS2300 for less than I can get another 3560G. If the RPS would have worked to give me more ports, it would not have been a waste of money, but as I understand now, it will not work.

Thanks for your reply.