On Wed, Feb 06, 2008 at 07:28:01PM -0700, Sherwood Botsford wrote:
> HOWEVER, these switches are dying like flies at a RAID show.
> I've had 5 of them die in the last 3 months. (I also use them in
> classrooms -- Overkill, for 3-4 computers in a classroom, but, as
> I said, the price is right.) In effort to stem the bloody tide,
> I've remounted them on the rack with 2 rack holes between each,
> to improve the air cooling.
>
> I'm wandering. New servers (wow! NEW, not second hand) are
> coming in. I'd like to set up a tiered structure, with the
> server switch being a GB switch, the second level switches being
> 1 GB uplink + 100 MBit to the desk top. Use 3 24 port ones in
> the wiring closet, and 12 port ones out in the classrooms.
>
> So I could put GB to the desktop -- except that my wiring is only
> Cat 5, and I don't really need GB at the desktop.
>
> So, question time:
I don't have an answer to either question. However, I do have questions
of my own.
This is just me, but here's how I'd approach it.
1. Given that for any switch, the more ports, the faster the
hardware in it has to be, therefore the more expensive (not just
for a bigger box and more connectors). I would determine a
range of connections in each classroom (the number of them).
E.g. if its 3-4 desktops, don't spend money on a 16 port switch
unless its free, or unless you can use 1-16 port switch for 4
classrooms.
2. Determine the level of service to the desktop: i.e. the speed
required. Partly, this is a function of what you expect the
students to do. If they only need email and simple web
browsing, they don't need a network speed to allow them to play
interactive games. Do they really need more than 10 MB/s?
3. Determine the traffic flow which you expect these switches to
cater to. If the desktops will be communicating with each
other between classrooms (within the classroom is covered by the
classroom switch), then it makes sense to go with a tiered setup
straight off if there are logical groupings.
4. If your building cableing will only handle 100 MB/s and not
1000 MB/s, then upgrading that will cost a lot (depending on the
physical plant) and its worth is dependant on question 2.
Once these questions are answered, you can then come up with 3 or 4
different ways of doing it, then price each out. If in your plan you
find you need 6-port 10/100 switches for the classrooms, it can be hard
to beat the little blue linksys boxes. I know that they are dinky home
units but at under $10? Put one in each classroom and run 100 MB/s to
the upstream server and configure the desktops to only link at 10 MB/s
(the switches themselves aren't manageable that I know of).
Then spend the money on good upstream switches. Its OK for a classroom
to go down for a few minutes if a little switch goes (have a spare on
hand), but you don't want the buidling infrastructure to go down.
Just my uninformed 2 cents.
Doug.
