On 12/25/10 6:42 AM, S Mathias wrote:
> Two questions that was not always clear for me [sorry for posting to this list :\]:
>
> ##############################################################################################
>
> Q1) when cabling, is the color order important? like:
>
> straight cabling:
> A side: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown
> B side: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown
>
> could be eg.: like this??
> A side: white-orange, brown, white-blue, green, white-green, blue, white-brown, orange
> B side: white-orange, brown, white-blue, green, white-green, blue, white-brown, orange
no. its critical that the pairs be maintained. ethernet uses
differential signalling on pairs. whote/orange and orange/white are a
twisted pair, as is each other combination of white/color and
color/white. the longer the cable, the more critical this becomes (eg,
you could perhaps get away with it on a 2 meter patch cord, but a 30
meter run in a wall would most certainly have crosstalk problems).
> ##############################################################################################
>
> Q2) again cabling.. i know what is the color order of straight and crossover cabling. BUT: what are the color orders, when i need to create physically two separated networks?
terrible idea. gigE uses all 4 pairs for a single connection anyways,
so you *can't* double up on a patch cord.
> 568B; straight; nic to switch:
> A side: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown
> B side: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown
> ----------
> 568A; crossover; nic to nic: [it's not so important about from ~2005]:
> switch the pairs: 1&2 with 3&6 on one side:
> A side: white-green, green, white-orange, blue, white-blue, orange, white-brown, brown
> B side: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown
568A and B aren't straight vs crossover. they are simply two different
schemes for the order of the pairs to the connector. basically, they
swap the green and orange pairs.
I would stick with T568A
> ----------
> one cable, two straight networks:
> A side:
> I.:
> II.:
> B side:
> I.:
> II.:
> ----------
> one cable, two crossover networks:
> A side:
> I.:
> II.:
> B side:
> I.:
> II.:
> ----------
> one cable, one straight and one crossover network:
> A side [straight]:
> I.:
> II.:
> B side [crossover]:
> I.:
> II.:
> ----------
> one cable, one crossover and one straight network:
> A side [crossover]:
> I.:
> II.:
> B side [straight]:
> I.:
> II.:
thats giving me a headache just thinking about it. DO NOT PUT TWO NICs
ON ONE RH45 CONNECTOR
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