2960 PoE Restrictions?

[John Blakley]

All,

I'm trying to figure out how these power requirements read out. The 296-48PST-S shows a chart like:

Table 2. Switch PoE Power Capacity

Switch Model	Maximum Number of PoE Ports*	Available PoE Power
Cisco Catalyst 2960-48PST-S	24 ports up to 15.4W 48 ports up to 7.7W	370W

This is the largest of the models that doesn't cost $6k. If I'm reading this right, does this switch really not support full power across all ports? It would be used for Avaya phones and wireless APs, so I'm needing something that can provide power across all ports. The next best one was model 2960S-48FPS-L which supplies 740w of power....

Thanks,

John

[Reza Sharifi · Accepted solution]

Hi John,

That is correct. At 15.4W which is class 0 for 802.3af classification, you can only use 24 ports for POE.  Most phones use less than 15.4W and according to Avaya their phones consume less power than Cisco phones, but you still have to reserve the max.

http://www.avaya.com/uk/resource/assets/whitepapers/Tolly210143AvayaVsCiscoVoIPPhoneEnergy.pdf

HTH

[John Blakley]

Thanks for that Reza I'm really trying to get our branches off of these Dell switches, so I'm trying to come up with the best (read cheapest) Cisco switch I can put on the edge that can run our phones/APs. It would be bad if we got some of these and only half of the phones powered up.

[Leo Laohoo · Accepted solution]

I'm trying to come up with the best (read cheapest) Cisco switch I can put on the edge that can run our phones/APs

Talk to your Cisco SE and ask them about the Technology Migration Program (TMP) which alot of SE's don't want to talk about.

I have a few of these 2960-48PST in our network.  And yes, they are relatively cheap but cannot provide full 15.4w PoE to all 48-ports.  This model will do, for 15.4w, up to 24-ports only at first-come-first-serve-until-full.

If you want all 48-ports to get 15.4w then the model you should be looking at would be the 2960S-48-FP.  This particular model comes in two "flavours":  2 x SFP/SFP+ (FPD) or 4 x SFP (FPS).  They come in slightly expensive because you can stack them (maximum of four switches in a stack).  Stacking module is optional.

[Reza Sharifi]

Hi Leo,

Good point on the 2960s stacking. I have never used the S series.  Have you?  How do you like them?

Thanks

Reza

[Leo Laohoo]

Hi Reza,

We like the 2960S because of how we deploy multiple switches in a cabinet.  So instead of the traditional daisy-chain or one-uplink-per-switch, we just stack them together (maximum of four switches per stack at 10 Gbps, full duplex, backplane) and then etherchannel back.  Not bad! 

Hey John,

Yes, TMP is THE trade-in program.  It is a large program:  router, switches, wireless access points, etc.  It's not a Cisco old to Cisco new, the TMP is designed to accept even competitor's product.

Like I said, of all the SE/AM I've spoken to, no one likes to discuss this.  They try their darn best to move away from the subject.  Don't even bother talking to an authorized Cisco reseller.

Have you ever seen, or do you use, phones across all ports on the model that you have?

We're a Cisco-shop so, yes, we have VoIP deployed in a variety of platforms, including 2960S.  We're slowly moving away from the legacy 2960/2960G and moving into the 2960S.  Also note that the 2960-series family will now allow you to enable limited static routing.

[John Blakley]

Interesting...I'll have to bring that up to our SE...

[Leo Laohoo]

I'll have to bring that up to our SE...

LOL.  Bring a video camera and watch him/her squirm.

[John Blakley]

Thanks Leo! What is the TMP? Is that a trade in program of some sort?  I looked at the model you described, and the best one that I would need  would be the one with 740W and that's the one that one is about  4500.00. Have you ever seen, or do you use, phones across all ports on the model that you have?

John

[Reza Sharifi · Accepted solution]

John,

The 2960 (none S series) are 10/100 with Gig uplinks and are pretty old.  If your company has the budget, I go with the 2960S series or 3560X. With the 3660X, the uplinks are on a module.  So, you could use a Gig module for now and if your company has the demand for more bandwidth later, you can change the module to 10Gig.

HTH

Reza

[John Blakley]

I'm going to look at the 3560x also...