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