Re: 2 Ethernet cabling question

[Mark Neidorff <mark@neidorff.com>]

On Saturday 25 December 2010 09:42 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
>
> ###########################################################################
>###################

The order was determined to minimize cross-talk on the adjacent wires.  Your 
best bet is to stay with the standard.  So, yes, the order is important.

>
> 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?
>
> 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 ----------
> 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.:
>
Please explain what you are trying to accomplish and at what network speeds.  
Off the top of my head, 10baseT networks used 4 wires and 100baseT used all 8 
wires.  If you are trying for 100baseT speeds, you have to use all 8 wires.

Did you notice how difficult the kind of cabling you want is to find?  There 
is a reason for that.

Mark