28-port or 52-port Core?

[catch21]

I've a dilemma. I'm replacing the core switch at my school. [i can re-use the existing switch as an access switch if necessary so that's staying in the rack.]

 

I need PoE so I can directly connect our 12 no. Ruckus APs to the core.

 

Clearly the server is going on the core, plus the firewall connection, photocopier, cache server etc and that's about it.

 

Just about everything uses the network over the wifi nowadays. All the children's laptops, staff laptops, most everything which means the copper network is basically redundant apart from WAP backhaul.

 

Great news then I've gone down from three core switches (loosely arranged in a stack) to one.

 

If I buy a 28-port switch (£600) it will be about 75% used on day one.

If I buy a 52-port switch (£1100) I'll have a load of spare ports but they may never be used.

 

The safe decision with someone else's money is to go for the 52-port switch. I don't always do safe decisions very well. If I buy a 28-port switch and genuinely need more core ports I'll buy another 28-port switch and interconnect them with 3 or 4 links in a LAG for example.

 

If I need more access ports next week I'll re-ignite the old core switch and re-deploy is as an access switch.

 

I don't know how two 28-port switches linked together would perform as a n/w core compared to a single 52-port although I would assume when the n/w is hugely busy, not as well.

 

I can't see an obvious decision here, 28-port or 52-port, do you have any thoughts?

[MordyT]

Get 2 28 switches.

Why? Well, if you do need more ports down the link you can link them together. But more importantly, if one switch fails you will have a backup one ready to roll. Best of both worlds

[catch21]

I like the thinking.

[john]

As someone who said just over a year and a bit ago that the 20ish spare spare ports on my core at one site and the dozen or so on the other site were plenty spare, I'm about to order another 48port switch to go into the stack which will be very much enough spare and cover the extra 12 NICs going in this month but you can never have enough as you can trunk server NICs etc... devices come with more than 1 NIC on most storage boxes etc...so you soon will use the spares up in a couple of newer servers.

[SYNACK]

It may have more to do with the specs than the ports, the backplanes on 52 port ones is probably much faster than the 24 port one, also the two switch suggestions is good if they have a really fast stacking interface. No stacking interface and you'll end up wasting lots of ports on linking the two together with decent bandwidth.

 

Also, as above you will end up burning a stack load of ports on new gear and putting core stuff on the end of an interconnect with other switches will slow stuff down.

Edited April 18, 2013 by SYNACK

[sidewinder]

As said, a good stacking interface and 2x28's may be the way to go, but don't do what I did and buy a 28 thinking youll never fill them, then buying a 52 port the year after because you filled them