[NTLUG:Discuss] LAN Planning

Kelledin kelledin+NTLUG at skarpsey.dyndns.org
Fri Aug 23 06:07:44 CDT 2002


On Friday 23 August 2002 04:52 am, Aaron Goldblatt wrote:
> I need some suggestions for designing a LAN I want to put into
> my (new, as in still-smell-paint new) house.

Well, now is probably the worst time for you to find this out, 
but it's best to start running cable within your walls before 
the drywall is up (but after the frame is complete).

> Objective:  Most of the computer equipment will be centered in
> a bedroom, but one computer won't be in that bedroom, and it
> is necessary to connect that computer to the LAN.

Good; hubs, switches, modems, routers, and most servers need to 
be centralized somewhere.  In a mid-sized home, an equipment 
closet is usually used for this purpose.

>
> CURRENT SETUP:
>
> I have two physically independent networks, one running
> 10.x.x.x, one
> running live IPs.  The live IP one runs 10BaseT.  The 10.x.x.x
> runs 100BaseT.  The private network is used for things like
> local IMAP, SMTP relay, and NFS.  The public network is used
> to connect to the
> net without the hassle of a proxy.
<snip>
> 1) A single physical network is nice but not strictly
> required.  The private side network must run 100meg.  The hub
> on that network is a
> 3Com 100BaseTX hub with a couple of fiber inputs.  It will
> -not- switch down to 10 megabits.

Best way to do this sort of thing is put the private network 
behind a router (a 486 running Coyote, Freesco, LRP, or even a 
full-blown distro is good for this).  Then set up a DMZ for your 
public servers, or just do port-forwarding for all services you 
want to be publicly accessible.

100baseT cards are outrageously cheap these days, even for good 
ones like Intel PRO/100's.

> 2) Easy to wire.  Patch panel optimal.  It can go in a closet.

Best way to keep the cable out of sight is to run it within 
walls.  To do this yourself, you have to get savvy on a few 
safety/electrical codes.  Here's a start:

1) You must use plenum-rated cable in all spaces that might be an 
HVAC return area.  Plenum-rated cable is specially designed not 
to omit opaque smoke/fumes if it catches fire.  It's typically 
used in the "plenum"--the space between the false ceiling and 
the structural ceiling--because this is commonly an HVAC return 
area.

2) Cables running within walls should be solid-wire in order to 
take a punch-down without fraying; cables running from walls to 
network units should be stranded for better flexibility.

3) Cables running within common walls must be run within 
insulating conduits.  Failure to do so is a code violation.

4) You must use riser cabling when running between floors.

A lot of these guidelines can unofficially be bent or even 
broken, primarily because health/electrical inspectors probably 
don't audit your house regularly.  I wouldn't break them though.

> 3) Easy to expand to additional ports.  Big patch panel?  (How
> many ports would be good?  This is a 4br 2150 sqft house.  I 
> want ports in at least three bedrooms, and possibly the formal
> living room which we're turning into a library.)

Two ports in each room is generally more than enough for a home 
setup.  The central area (the equipment closet/room) will need a 
lot more ports, simply because this will be where all electronic 
roads lead. ;)  For your floor plan, it looks like a 16-port 
wall-mounted patch panel would be enough for the equipment 
closet.  A 24-port would give you a lot of room to grow, but 
that would probably be more expensive.

> 4) The Internet connectivity will be coming through some sort
> of 10BaseT port, either an Ascend Pipeline 50 or 85, or some
> kind of xDSL modem/router thing.  This means that a proxy is
> necessary unless we go with two physical LANs.

A proxy is not always necessary; a router usually is, however.

> 5) Money is an object, but plenum cable is absolutely
> required. Please tell me where it can be found at the
> price-performance sweet spot.  :)

Good that you recognize that. ;)

Greybar Electric, Grainger, and Home Depot all provide pretty 
reasonably-priced cable (though I don't know if Home Depot will 
provide plenum-rated); I've taken to getting bulk cable cut off 
the spool in specified lengths.

> 6) In that same line of thought, does somebody have a
> punchdown tool I can borrow, or know where can I get one for 
> not-a-lot?  Will also need wall plates, wall plate pop-ins, 
> male RJ45 ends, and a crimper.

Wall plate pop-ins are commonly known as keystone jacks, btw.  I 
have a few of those left, but not enough to satisfy your needs.  
Leviton keystone jacks and faceplates can be had at Home Depot; 
they're of reasonably good quality.  The best keystone jacks are 
manufactured by Panduit, but they're rather difficult to come by 
locally.

However, I have gobs of male RJ45 ends, as well as a decent RJ45 
crimper and a 110/66-style punch-down tool.  I'd probably never 
use the RJ45 ends, except doing just this--crimping cable for 
someone else's installation. ;)  I used to have a nice little 
Cat5 jacket stripper, but that's currently missing.

> 7) If we locate a wiring closet in one of the bedroom closets,
> what can be done to make the hole in the ceiling pretty?  Just
> leaving an empty hole isn't a good idea.  Would piss off the
> wife major bad.

I'll have to look that up.  IIRC there's actually some 
fireproofing you're supposed to do with that sort of thing 
(along with using riser cable).

> 8) Is there a standard color pattern for wiring in a house? 
> When I've built cables, I've done it like this (hook facing
> away):

> LEFT
> Orange-White
> Orange
> Green-White
> Blue
> Blue-White
> Green
> Brown-White
> Brown
> RIGHT

What you've listed there is 568B, the standard color-pattern for 
wiring Ethernet.  There's a somewhat older standard (568A) 
that's essentially the same as 568B, except the green and orange 
pair are swapped.  You shouldn't have to worry about 568A unless 
you want to make a crossover cable (unlikely).

> 9)  There is a lack of telephone jacks in this house (only one
> in the kitchen and another in the master bedroom).  I know
> it's certainly possible to run landlines on the unused CAT5
> pairs; is it wise? Should I simply drop new line?

Drop new line.  Running lines on the unused CAT5 pairs is 
technically possible, but it will make the network incompatible 
with standards like copper Gigabit (if you ever plan to 
upgrade).  Copper Gigabit uses all four pairs.

> 10) For each faceplate I was planning two RJ45 ports, each
> with it's own 4 pair lead.  Should I simply consolidate them
> and go for using all four pairs, forgetting for the moment the
> landline issue?

See above.

> 11) Wiring closet in the bedroom closet, or in the garage? 
> Garage is not AC'd (obviously), which is my only major concern 
> about putting it there.

If the wiring closet contains cable only, it may be OK for the 
garage (I personally would prefer bedroom closet).  If it 
contains sensitive electronic equipment, you need 
climate-control that a garage usually doesn't offer.  In either 
case, DO NOT run cable on open ground; just keep it indoors or 
in the garage.  Running cat5 outside is a whole other can of 
worms.

> IN THE ALTERNATIVE, should I simply forget wiring the walls
> and go for the 802.11x solution for the one computer not in the
> bedroom? If I do, I'll have a number of walls to go through, 
> all sheetrock.

802.11x is definitely easier.  However, Cat5 is a lot faster and 
a lot more reliable (and once you get past running cable in the 
walls, the hardware's a lot cheaper).  The kind of wiring you're 
doing might set you back enough to offset the cost savings of 
hard lines, though.

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




More information about the Discuss mailing list