[lug] testing for straight versus cross-over patch cables?

[j davis]

ok....almost anystore you go to now sells yellow crossover cables and
all the ones i have say crossover on the jacket....i got 2 cables from qwest
one from Baillos of Santa Fe and another from Best Buy in Boulder...all 
yellow
all say crossover .....yes i am sure you can get custom colors but i f you 
are
buying cables from a store.....crossover seems to be yellow more often than 
not

jd


>From: Nate Duehr <nate at natetech.com>
>Reply-To: lug at lug.boulder.co.us
>To: lug at lug.boulder.co.us
>Subject: Re: [lug] testing for straight versus cross-over patch cables?
>Date: 12 Aug 2002 02:04:37 -0600
>
>
>On Sun, 2002-08-11 at 21:00, j davis wrote:
>
> > also....i know everyone know this but...
> > generally if the cable is yellow its a crossover cable and
> > sometimes the outside shielding  will say "crossover" really small too.
> > all ot the above only applies to pre-manufactured cables.
>
>Don't take this the wrong way but...
>
>Bzzzt.  Wrong.
>
>You can order cables of whatever pin-out you like in whatever color you
>like from multiple vendors.
>
>Yellow is definitely NOT any kind of standard on what pin-out the
>connectors are configured as.  (I have at least four yellow
>straight-through, commercially-manufactured cables in my basement right
>now... one of which is definitely beyond the normal working length for
>Ethernet too... gotta love cable manufacturers... they'll build
>anything, even if it will break your network...)
>
>Also, I have never seen a bulk cable manufacturer print anything about
>the pin-out of the cable on the jacket.  (Remember, there is no shield
>on UNSHIELDED TWISTED PAIR [UTP] cable.)
>
>Any vendor that does is probably charging you too much for the cable
>anyway, as the machines to label thousands of feet of UTP cable jackets
>with "cross-over" are going to add unnecessary cost to the product.
>
>However, the sad state of the computer industry is probably such that
>maybe they really are doing this now... people don't bother to learn the
>relationship between two silly pairs of wire anymore... pins 1,2,3 and 6
>are all that you need to know to make any Ethernet cable your friend...
>
>Ahhhh... no one remembers the joy of DTE/DCE serial cables, eh?  In
>fact, if you look at the electrical properties of a data circuit and
>realize that's all Ethernet is... it becomes amazingly clear why you
>have 2 pair, and why they have to cross when connecting to two "DTE"
>devices... whereas a switch or hub is a DCE device, to use the old
>terminology...
>
>Ever had a cable that had the internal color code screwed up (never did
>find exactly where... but the colors crossed inside the cable, which
>meant it had been SPLICED inside, and that's bad...) and LOOKED correct
>but wasn't when you took a VOM to it?  I have.  Once.  Wasted a lot of
>time figuring THAT one out... of course, Cat 5 was hideously expensive
>back then also, and we weren't wasting any of it...
>
>Personally, I buy PINK cross-over Ethernet cables to carry around with
>me and take to customer sites, after a friend of mine started it as a
>joke.  The joke started at a company I worked for that seemed to think
>everything needed to be certain colors instead of having technicians
>that were smarter than the cables they were using... so since he was
>writing the specification with that in mind... the purchasing folks
>happily bought pink stuff for some specific connections to a specific
>network device that had to be wired directly to another terminal
>device....
>
>They're immediately noticeable, and no self-respecting
>testosterone-laden network jock fresh out of Cisco "engineering" courses
>who can't build his own cables will steal them from my laptop bag while
>I'm not looking.  :-)
>
>(No offense if there are any testosterone-laden Cisco-jocks present... I
>just get a serious belly laugh out of someone who can program some
>monster 150+ port Ethernet device who can't make an Ethernet cable from
>memory... it's so wonderfully ironic... if you really want to get me
>started, let's talk about not using RJ45's built for stranded conductor
>wires on solid conductor Cat 5... yes, there *IS* a difference in
>RJ45's... and it won't bite you until you build about 300 of them in a
>weekend... or should I say, not until Monday morning, anyway...)
>
>Sorry, I'm ranting, and it's not directed at you, JD.  I'm pushing over
>windmills here, methinks...
>
>--
>Nate Duehr, nate at natetech.com
>
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thanks,
jd

jd at taproot.bz
http://www.taproot.bz

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