Self made network cables.

[vetplus40]

Thought I would pass along this bit of info.If you decide to make your own cables,follow one of the standards correctly.I did NOT do this ,and as a result spent considerable time troubleshooting what turned out to be a wiring mistake.Just wanted to share this so that others might learn from my mistake...

 

[skyking]

It does not cost any extra to be nice

A good sig!

 

[ScottMac]

Just for reference (and my own personal curiousity), what kind of errors were you getting?

This is pointed out here all the time (using a EIA/TIA 568 standard for cabling), and sometimes it useful to have some references to point to when the inevitable "I didn't and my setup is working just fine" responses.

Thanks

Scott

 

[skyking]

Sound like a split pair condition, Scott?

 

[vetplus40]

The first mistake I made was trying to wire a network like I do an instrument control loop at work.We keep the pairs "paired" up.Easier troubleshooting that way.
The first page I saw on how to do this had a different color scheme than my cable did.It had a green with a white stripe/white with a green stripe layout.My cable has solid colors with corresponding white striped wires.Next error was that I didn't look close enough at the page I found that had a layout that went white/orange and solid orange.I then transposed the next pair of white/green and blue,to white/green with green.I continued to pair the remaining wires this way.
The only problem I had was with auto negotiation. As long as I set the NIC to 10Mb/s it worked. Any other setting ,and it would not work.

 

[narzy]

and the correct standard is...drum roll please

wo / o / wg / b / wb / g / wbr / br

white orange / orange / white green / blue / white blue / green / white brown / brown left to right pins facing up. just for reference I forgot what you switch on what end for a cross over cable seeing that I never use the damn things .

 

[ScottMac]

Yeah, split pair, fer sher.

Crossover is: swap the orange and green pair (1&2 with 3&6) on one end, keeping the stripes and solids in the same order (polarity counts on most devices).

The next most common mistakes are:

Stripping off too much jacket (the cable sheath should be crimped under the dimple)
(usually improperly done at the same time .....)
More than 1/2 inch (~1 cm) of untwisted pairs (...hanging out of the connector with no strain relief)

Bends that are too sharp: there should be at least a two inch (~4cm) radius to any bends in the cables along the entire span. One place that get's overlooked is in conduit; if the installer pulls too tightly on the cable, a 90 degree bend (with jacket deformation) occurs at some junctions.

Compressed sheaths (the jacketing on the cable should not be compressed to the point of deformation)

Over-stretched cables (when pulling UTP, the recommended pulling tension is less than 14 pounds for many/most/all UTP)

(there'd be a whole section on using UTP outdoors .... but that's been covered enough).

Thanks for the info VetPlus. It'll be helpful.

FWIW

Scott

 

[SrASpeedRacer]

Another common thing you might run into it the Green and Orange pairs are switch in a straight through cable! It really doesn't matter wire is wire, but if your in a hurry and only look at one end you might mistake it for a crossover.