I'm helping my friend punch down all of the Cat5-e cable in his office. Some of it went to existing patch panel and some went directly into a switch. There are two patch panels, each was about half full. We punched down about 12 cables into the first patch panel, following the same pinout as the rest - T-568A. We moved on to the next patch panel and followed the pinout labeled on it, which was T-568-B. After finishing it, we tested all cables and they worked fine. Then we realized we probably built some cables that have pinout A on one end and B on the other. From what I have read, on a 10/100 network (which they are on), having one end be A and one end B doesn't matter. We obviously have to fix this but I have two questions:

  1. On the 10/100 network, will they have any issues using a cable that has one end with pinout A and one end with pinout B?
  2. If we have cables with pinout A going from the wall to the patch panel and then we use a Cat6 cable with pinout B from the patch panel to the switch, is that going to cause any problems? I'm guessing not but just want to confirm. We are planning on upgrading the switches to 1 Gbps.


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You have a cable which has the transmit and receive pairs reversed on one end, basically, a crossover cable for 10/100 Mbps. Also, 1 Gbps uses all four pairs. A lot of things today have Auto MDIX, and they should be able to adjust, but not everything does have this, and those things won't work unless you use a crossover patch cable on one end (not both ends) of the horizontal cable.

By the way, why go to the expense of Category-6 patch cables if the horizontal cable is Category-5e? This is completely useless, and could lead someone to believe that the horizontal cable is Category-6 when it is not. A cable plant should use the same rating throughout because the rating of the cable plant is the rating of the lowest rated link.

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