4w ago

Can't have those nice pairs after all 😔

15 comments

Yeah, why is this the case? I have to refer to a diagram whenever I punch down a jack. Always forget where the green goes.
- They made 2 variations so it could coexist with older Telco wiring.
- Blue in the middle is pair 1. Orange around that is pair 2. Green on the left, brown to the right.
  CC-B-AA-B-DD.
  Pair A is for telephone back when Ethernet was wired to a punch down block. Pair B and C are for data. Swap b and c on one end for crossover.
  The fourth pair is basically useless.
- To prevent crosstalk inside the cable and between cables in the same location, among other reasons.
Tab down, orange white, orange, green white, blue, blue white, green, brown white, brown.
But in all honestly as long as the cables match on either end it doesn't matter even in the slightest what color they actually are so I never understood why they used such weird pairing either.
- It matters for longer runs and higher speed. The twist provides noise cancellation effect
  
  It matters that you do the pairs right. CC-B-AA-B-DD. It doesn’t matter which color is which, except to make it easier to get the ends to match.
- dick down, orange to brown
  
  If you're blue inside, it ends in shit
When Metcalfe created Ethernet it was Thick Coax. Ethernet over twisted pair was standardized by TIA. They didn't fuck with it. They created it. Before that it was vendor specific.
I don't know where they found it, but the WISP who ran Ethernet from the antenna to the router in my mom's house used white jackets for every wire pair.

15 comments