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 :]:
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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).
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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