Solved: Catalyst 3560E

abbas.ali · ‎08-30-2007

Is it true that only Catalyst 3560E-48PD-SF supports POE for IP Phones on all 48 ports. I wanted to go with 3560E-48PD-S, but on CCO it shows that this model only supports 48/24. Does that mean that only 24 ports out of 48 will be able to supply power to IP Phones.

theobagm · ‎09-02-2007

The difference between the 3560E-48PD-S and the 3560E-48PD-SF is the installed PSU. The -SF ships with the 1150W PSU while the -S has the 750W unit. Do the math 48 ports at 15.4W is 739.2W, and the switch itself needs more than 10.8W to operate so with the smaller PSU there is not enough power to provide ALL 48 ports with the full 15.4W required by the 802.3af standard. There are many devices that can operate at the lower 'cisco pre-standard' power level of 7.7W that could be supported on all 48 ports with the 750W PSU. But since the switch is documented as an 802.3af standard switch they can only claim to support 24 ports with the smaller PSU.

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okuehn · ‎09-20-2007

i think you do not have trouble even with the NON-E 3560 as long as you are using cisco phones. most of them work as lower 6.3V devices and are negotiated automatically by CDP.

http://www.cisco.com/en/US/products/hw/phones/ps379/products_qanda_item09186a00808996f3.shtml#qa3

Q. What are the power requirements for the various models of the IP phone models?

* CP-7902G (6.3W)

* CP-7905G (6.3W)

* CP-7910-SW (6.3W)

* CP-7910G (6.3W)

* CP-7912G (6.3W)

* CP-7940G (6.3W)

* CP-7960G (6.3W)

* CP-7906G (5W) (Class 2)

* CP-7911G (5W) (Class 2)

* CP-7941G (6.3W) (Class 2)

* CP-7941G-GE (12.9W) (Class 3)

* CP-7961G (6.3W) (Class 2)

* CP-7961G-GE (12.9W) (Class 3)

* CP-7970G (10.25W) (Class 3)

* CP-7971-G-GE (15.4W) (Class 3)

* CP-7985G (12.55W) (Class 0, Not full brightness)

* IEEE 802.3af Device - Class 0 (15.4W)

* IEEE 802.3af Device - Class 1 (4W)

* IEEE 802.3af Device - Class 2 (7W)

* IEEE 802.3af Device - Class 3 (15.4W)

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srue · ‎08-30-2007

are you sure you dont mean the 3750?

The Cisco Catalyst 3750-E 48-port PoE configurations can support 48 simultaneous full-powered PoE ports at 15.4W when using the optional 1150W power supply.

http://www.cisco.com/en/US/products/ps7077/products_data_sheet0900aecd805bbe67.html

or, for the 3560..

The Cisco Catalyst 3560 Series 24-port PoE configurations can support 24 simultaneous full-powered PoE ports at 15.4W for maximum powered device support. Using Cisco Catalyst Intelligent Power Management, the 48-port version can deliver the necessary power to support 24 ports at 15.4W, 48 ports at 7.7W, or any combination in between. The Cisco Catalyst 3560 Compact Switch can support 8 simultaneous full-powered PoE ports at 15.4W.

Pari Thiagasundaram · ‎08-30-2007

You can order the C3K-PWR-1150WAC or order the Cisco RPS 2300 along with your 3560-E.

Hope the following link would be more useful to you.

http://www.cisco.com/application/pdf/en/us/guest/products/ps7078/c1650/cdccont_0900aecd805bac22.pdf

abbas.ali · ‎08-31-2007

Thanks,

But, I am still confused about the two models. It seems that they both will support POE on all 48 ports, but 3560E-48PD-SF will support POE on all 48 ports at 15.4W, and 3560E-48PD-S will only support POE on all 48 ports without 15.4W

Does that make any difference.

Thanks,

theobagm · ‎09-02-2007

The difference between the 3560E-48PD-S and the 3560E-48PD-SF is the installed PSU. The -SF ships with the 1150W PSU while the -S has the 750W unit. Do the math 48 ports at 15.4W is 739.2W, and the switch itself needs more than 10.8W to operate so with the smaller PSU there is not enough power to provide ALL 48 ports with the full 15.4W required by the 802.3af standard. There are many devices that can operate at the lower 'cisco pre-standard' power level of 7.7W that could be supported on all 48 ports with the 750W PSU. But since the switch is documented as an 802.3af standard switch they can only claim to support 24 ports with the smaller PSU.

abbas.ali · ‎09-20-2007

Hello Theobagm,

Thanks for your reply and clear the confusion. However if I decide to go with 3560E model, then I have a choice to pick between S vs SF, but my customer is now wants to go with Standard 3560-48-PS switches, and wanted to confirm if this model will have the same issue. I just checked on Cisco's website, and it is also labeled 48/24. I don't know if this model can support 1150W PSU or not as it is not mentioned on CCO. What will be the solution then?

jcoke · ‎09-20-2007

The PS in the 3560 series (read: non-E) is fixed. Your customer is limited to 48 class 2/24 class 3 or some combination of the 2. The "solution" in this case is to buy 2 WS-C3560-24PS.

abbas.ali · ‎09-20-2007

I have seen lot of companies have bought 3560 Non-E 48-PS switches and never reported any problem that only 24 out of 48 IP Phones were able to powered on. Why one will buy 48 port POE switch if it can't supply power to all 48 ports.

jcoke · ‎09-20-2007

Power consumption-wise, all phones are not equal. Those companies are probably using prestandard phones or current generation class 2 (7.0W) phones. A company that bought all gig-e phones and 1131AG APs - both .af class 3 (15.4W) - with non-E 3560s would complain, loudly. You've got 370W of PoE power on that switch, period. How you use it is up to you.

**Sorry if this shows up multiple times, I think the form servers are built on top of a graveyard or something.

abbas.ali · ‎09-20-2007

Hi jcoke,

This company has standard Cisco 7960G phones. Don't know if NON-E 3560 or 3750 switch would be able to handle 48 phone per switch or would be better off buying 24-port NON-E switch.

okuehn · ‎09-20-2007

i think you do not have trouble even with the NON-E 3560 as long as you are using cisco phones. most of them work as lower 6.3V devices and are negotiated automatically by CDP.

http://www.cisco.com/en/US/products/hw/phones/ps379/products_qanda_item09186a00808996f3.shtml#qa3

Q. What are the power requirements for the various models of the IP phone models?

* CP-7902G (6.3W)

* CP-7905G (6.3W)

* CP-7910-SW (6.3W)

* CP-7910G (6.3W)

* CP-7912G (6.3W)

* CP-7940G (6.3W)

* CP-7960G (6.3W)

* CP-7906G (5W) (Class 2)

* CP-7911G (5W) (Class 2)

* CP-7941G (6.3W) (Class 2)

* CP-7941G-GE (12.9W) (Class 3)

* CP-7961G (6.3W) (Class 2)

* CP-7961G-GE (12.9W) (Class 3)

* CP-7970G (10.25W) (Class 3)

* CP-7971-G-GE (15.4W) (Class 3)

* CP-7985G (12.55W) (Class 0, Not full brightness)

* IEEE 802.3af Device - Class 0 (15.4W)

* IEEE 802.3af Device - Class 1 (4W)

* IEEE 802.3af Device - Class 2 (7W)

* IEEE 802.3af Device - Class 3 (15.4W)