[NTLUG:Discuss] LAN Planning

[Kelledin]

On Friday 23 August 2002 02:57 pm, Aaron Goldblatt wrote:
> What's the theory behind this?  Fire in the wire leaking smoke
> into both rooms?

Conduits serve as electrical shielding (although a metal conduit 
increases attenuation a bit) and cable protection.  In this case 
I suspect the requirement is for electrical shielding.

> I don't know what you mean "between floors."  It's a
> single-story house, and the foundation is slab.  No running
> under the floor here.

If you plan to run cable through a ceiling, you can't just punch 
a hole for it.  Part of the ceiling's purpose is to stop the 
spread of fire, and a hole in that ceiling works like a 
chimney--it may let out smoke, but it also feeds the fire with 
fresh oxygen and gives it a path to spread.

For going through anything that serves as a fire barrier, you're 
supposed to make sure it stays sealed during a fire, even after 
you've got the cable run through it.  This is commonly done by 
running the cable through a "poke-thru" spacer, cutting a hole 
that matches the spacer, and lining the mating surface of the 
spacer with "intumescent" material--i.e. material that expands 
under high heat.  If a fire starts, the intumescent lining 
becomes a very effective gasket.  Using riser cable (should be 
only slightly more expensive than general-purpose cable) is also 
a requirement for its marginal fire-resistance.

I've never done this myself; I just remembered that detail from 
one of my reference books.

Also, I found a site called wiremold.com that carries products 
you might be interested in.  A lot of their stuff is sold 
locally at Home Depot, but their site's worth a look if you want 
some ideas.  A lot of their stuff is great for people having to 
run cables *after* the drywall is up.

> The reason I've indicated a proxy is the 100BaseT requirement
> because of my non-step-down hub.  Anything coming in on
> standard xDSL or ISDN equipment is going to be 10BaseT only,
> and won't link to my hub.

The way my network works is this:

An old 486 box contains two NICs--one 100baseTX, one 10baseT.  
The 10baseT connects to the cable modem, which connects to the 
outside world.  The 100baseTX port connects to the switch on my 
LAN at 100Mbit full-duplex; the 10baseT never touches the 
switch.  All the boxen on my network share the same public IP 
address (skarpsey.dyndns.org). All the internal boxen connect to 
the same switch at 100Mbit full-duplex (except for the main 
workstation, which connects to the switch via fiber Gigabit).

Maybe I'm missing something, but I would think you could do much 
the same, even with your switch...just all the internal network 
ports have to work at 100baseTX.  Whatever NIC is dedicated to 
the cable/DSL modem can be just a mere 10baseT, and the switch 
won't care.

> I suppose I'm looking at a couple hundred dollars if I max out
> at 2400m of cable?

Close to that, yes--depending on how much has to be plenum-rated.  
At Home Depot, 1000' spools of cable are a little over $50 
apiece for general-purpose cat5e (good for 10/100 and sufficient 
for copper Gigabit).  Plenum-rated cable is about three times 
that price.  Home Depot will allow you to purchase either by the 
foot, but it costs about two or three times as much per foot 
doing that.

A patch panel and faceplates may be another $100-200.  I don't 
recall seeing such things at Home Depot, but I've seen them at 
Micro Center and PriceWatch.  I've also seen bulk cable, 
faceplates, and keystone jacks at Micro Center, but their 
quality was not all that impressive.

I expect wireless is looking better and better now. ;)

-- 
Kelledin
"If a server crashes in a server farm and no one pings it, does 
it still cost four figures to fix?"