Cable Forum - View Single Post - Recomendations for purchasing network gear for office

Graham M · 24-07-2008, 11:51

Type B is more widely used but it doesn't matter if you mix Type A and B so long as you terminate each one the same at both ends as Type A and Type B are the same just with 2 pairs of wires swapped over. If you wire type B at one end and type A at the other, it becomes a crossover cable.

Type B goes White/Orange, Orange, White/Green, Blue, White/Blue, Green, White/Brown, Brown

Type A goes White/Green, Green, White/Orange, Blue, White/Blue, Orange, White/Brown, Brown

As you can surmise from this, the only 2 pairs that are actually used are the Green and Orange ones but it is normal to wire all 4 pairs up, if a wire breaks you can change the pairs used instead of doing a re-pull for instance. It is possible to run 2 devices on one wire but it is tricky as you have to separate out the 2 sets of cables into separate plugs and get them in the right slots which can be fiddly in RJ45 connectors but not so difficult on patch panels and sockets, of course you could end up with noise over long distances although I have run this successfully without problems over 20metres.

24-07-2008, 11:51	#7
Graham M - Join Date: Jul 2003 Location: Poole, Dorset Age: 40 Services: FreeSat+ Tivo V-Box VM 60MBit Posts: 13,365	Re: Recomendations for purchasing network gear for office Type B is more widely used but it doesn't matter if you mix Type A and B so long as you terminate each one the same at both ends as Type A and Type B are the same just with 2 pairs of wires swapped over. If you wire type B at one end and type A at the other, it becomes a crossover cable. Type B goes White/Orange, Orange, White/Green, Blue, White/Blue, Green, White/Brown, Brown Type A goes White/Green, Green, White/Orange, Blue, White/Blue, Orange, White/Brown, Brown As you can surmise from this, the only 2 pairs that are actually used are the Green and Orange ones but it is normal to wire all 4 pairs up, if a wire breaks you can change the pairs used instead of doing a re-pull for instance. It is possible to run 2 devices on one wire but it is tricky as you have to separate out the 2 sets of cables into separate plugs and get them in the right slots which can be fiddly in RJ45 connectors but not so difficult on patch panels and sockets, of course you could end up with noise over long distances although I have run this successfully without problems over 20metres.