network architecture - switch issue...

[Brad Pears]

We are looking at upgrading part of our network backbone.

We have five servers - three in one building, two in another. Each building
has a 24 port 10/100 Dell cheap switch in it and the building are connected
using a single CAT5 connection buried in the ground. All our wiring is cat
5.

What I am looking at doing is replacing the two 10/100 switches with gigabit
switches - possible managed (but not sure if required). This will provide
full gb access between the two buildings - between all the servers (they
have built in gb NICs). Next, I want to upgrade a portion of our office area
desktop machines to gb NICs to give them speedy access to all the data they
need. They use CAD stuff so the drawings are large to load over the network

My question is this... In looking into pricing, one can purchase (for
example - using Dlink products...) a basic 10/100/1000 8 port gb switch
(unmanaged) for $119 then you can step up to a "Smart" switch then to
managed layer 2/3/4 etc...

The Dlink 8 port switch reads as follows...

"The D-Link DGS-1008D 10/100/1000 Mbps Gigabit Switch features a
non-blocking switching architecture that filters and forwards packets at
full wire-speed for maximum throughput. An 8,000 MAC address table provides
scalability for even the largest networks. Address learning and aging,
802.3x Flow Control for full duplex mode, and back pressure flow control for
half-duplex mode alleviates traffic congestion and ensures reliable data
transmission."

I am not a techie on communications products - but it sounds like this
switch would likely meet our needs. We only have 50 machines on our network
and I am only wanting gigabit between the serves and for our 5 designers....
Maybe more down the road but not right away...

What are the benefits of going managed and further going to a layer 2/3/4
switch as I am assuming this one above is simply a layer 2 switch??

Thanks,

Brad

 

[Phillip Windell]

We are looking at upgrading part of our network backbone.

We have five servers - three in one building, two in another. Each building
has a 24 port 10/100 Dell cheap switch in it and the building are connected
using a single CAT5 connection buried in the ground. All our wiring is cat
5.

------<shortened for space>------

I don't see any over-all problems except that the CAT5 isn't going to handle
the GIG speeds very well, if at all,...if it can't handle it then you may
end up with even slower speeds then if you left it as 10/100. GIG speeds
need CAT6 or CAT7 with a minimum of at least CAT5E to really be dependable.

The fact that you are transfering CAD files doen't mean much because they
are not constantly transfering,...they transfer, they open in the CAD
program and that is it,...there is no traffic on the line as you work on the
file. RAM and CPU is where the load is, not the network wire. In the end
they are no different than transfering any other kind of file,...files are
just files as far as the network is concerned.

What are the benefits of going managed and further going to a layer 2/3/4
switch as I am assuming this one above is simply a layer 2 switch??

Unless you need a Router and have split the system up into subnets,...there
would be *no* benefit. If you aren't having problems with "broadcasts" (no
indication you are) then there is *no* benefit to splitting into subnets.
The type of traffic you described is "directed" not "broadcasted", therefore
Layer2 Switching is all you need,...so don't waste $$$.
There are no Layer2/3/4 Switches. A regular Switch is Layer2. A Layer3
Switch is just a Switch (L2) and a LAN Router (L3) built into the same piece
of hardware. The "Router" portion of it may not be as advanced as a regular
LAN Router, but they are still pretty good. Ours is from HP and works
well,..with the Duel Power Supplies and Modules we needed to add, it cost
around $10,000.00

 

[Richard G. Harper]

I'll second all of what Phillip said, but add a new thought ...

The major factor that will impact network performance is the fabric
(internal backbone) of each switch. A gigabit switch may sound good, but if
the fabric can only handle two gigabits throughput you're looking at
swamping the switch pretty quickly.

As my grandfather used to say, "Quality you pay for once, cheap you keep
paying for."

--
Richard G. Harper [MVP Shell/User] (e-mail address removed)
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