568A or 568B


  #1  
Old 05-20-03, 10:27 AM
jacdan
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Question 568A or 568B

I do commercial construction in the day and work network repairs/moves in the evening and I always wanted to know why the 568a/b difference. It seems that most of the residential go the way of the 568A tia standards and the commercial guys go with the 568B standard. The leviton folks are slightly skewed to the residential side and offer jacks that offer a choice, but some of the others like Panduit are mostly 568b. Is the difference just in the size of the cabling infrastructure that determines the standard? Thanks.
 
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Old 05-22-03, 10:41 PM
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The only things I can think of are termination color codes. 586A is the newer standard; most new instillations are done with 568A. The government requires all new contracts to use 568A. Basically the AT&T standard (258A) evolved to 568B. There fore 568A is more backward compatible.


EIA/TIA-568A:
Pin 1: White/Green
Pin 2: Green/White or just plain Green
Pin 3: White/Orange
Pin 4: Blue/White or just plain Blue
Pin 5: White/Blue
Pin 6: Orange/White or just plain Orange
Pin 7: White/Brown
Pin 8: Brown/White or just plain Brown

EIA/TIA-568B:
Pin 1: White/Orange
Pin 2: Orange/White or just plain Orange
Pin 3: White/Green
Pin 4: Blue/White or just plain Blue
Pin 5: White/Blue
Pin 6: Green/White or just plain Green
Pin 7: White/Brown
Pin 8: Brown/White or just plain Brown
 
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Old 05-25-03, 08:23 AM
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From what I have read in the standard and in papers on installation and use, one uses the more logical arrangement of wires the way they peel from the twist and the other one is just the way it is. As far as I know there is no practical difference.

When I wired my house, I used the first one I came to in the wiring diagrams and stayed with it.

Hope this helps.
 
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Old 05-28-03, 08:56 PM
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One main difference between the two is used when cabling two computers together or when connecting one hub to another. When connecting two computers a crossover cable is needed. Basically use 568A color code on one end of the cable and 568B color code on the other end. This crosses the data transmit and receive cables so the machines and talk to each other. The same method is used when connecting hubs. 568A on one end and 568B on the other. Output of one hub to input of other hub. When connecting computer to hub straight pass through is used, 568A on both ends. On the rj45 jack pins 1,2 are data receive and pins 3,6 are data transmit. These are the only pins that need to be reversed in a cross-over situation.
 
 

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