Re: [school-discuss] Cat-5 question

[Quentin Smith <quentins@comclub.dyndns.org>]

Hi-
On Wednesday, August 14, 2002, at 04:04  PM, Jim Aird wrote:

> 1.  Keep 18" or more away from fluorescent lights.
>
> So, runs in an attic that go above lights may be a problem??  Yikes!
Yes, although I've never really had problems with that.

> 2.  Just be sure that the pairs match up to the pattern:
>
> AaBCcbDd
>
> ...or if you prefer colours use O=Orange U=blUe G=Green N=browN as follows 
> (the colours do actually have a proper order, but I can't remember what it 
> is, and it shouldn't matter within the one cable, as long as the pairs work 
> out), capital being solid colour and lowercase being striped/white:
>
> OoGBbgNn
>
> Crimping any old how works for short cables, not for long. `Long' is a greater 
> distance for 10Mb than 100Mb. An example of a typical _WRONG_ pairing is:
>
> OoGgBbNn
>
> The last example is exactly what I have been using (and have had no problems except in the longest run)  I realize this is convention but does anyone have any experience using a non-conventional pairing and having performance increases when switching (has changing fixed the problem?) to the convention?  I am just wondering if I should pull the works, get another box of cable and do it all over or if maybe I can salvage what I have by replacing a few ends with the right pairing.
Exactly, just re-do each end of the cable. This has bitten me more than once. Remember, the maximum length of a twisted pair line is 300 feet, and and mistakes with installing the line will be more accentuated the closer to 300 feet you get. And if you do decide to pull the cable (maybe because of the flourescent lights), remember that 10BaseT will probably work on the line.
> I appreciate all the helpful responses and will wait til this after noon to decide my own fate.  Maybe you who are in the know can "vote" on how HomeTech Charter School can be operational by the beginning of school.
I'm not sure what the vote is for, but here's my vote: it's going to work perfectly, and then fail spectacularly just when you need it. ;)
Good luck,
--Quentin
> Also, we will be deploying a four server internet, DMZ with web and mail, local host/squid,proxy and admin network solution.  If anyone wants to help install and test our solution or you want to see a school-wide solution without commercial software in action, send me mail and I can let you know where and when.
>
> Jim Aird
> HomeTech
>
>
>
> > -----Original Message-----
> > From: Jim Aird
> > Sent: 8/14/02 1:09 AM
> > Subject: [school-discuss] Cat-5 question
> > I just got a new box (1000ft) of cat-5 cable and made five new runs
> > through my office but couldn't get the links to come up.  After several
> > hours of troubleshooting, re-crimping cables, moving hardware etc. I
> > discovered that the new cable (four twisted pairs) is conducting on many
> >
> > tiny fibers of copper while the rest of our building, running fine, has
> > a solid piece of copper within each of the 8 individual strands.
> > Otherwise there is no difference.
> >
> > Am I going nuts or is there something to the solid piece vs. the many
> > tiny strands difference?
> >
> > Any help within the next 1-24 hours would be a huge help, so I can be
> > ready to drop in our new set of servers and firewalls and offer internet
> >
> > filtering (squid) and related services to the students by the first day
> > of school.
> >
> > Jim Aird
> > HomeTech Charter School