Which is correct?

they are both correct, depending on the specification. If you are
passing it through the wall from an existing connector, just copy what
is on the existing connector.

If you've removed the connector and don't know which one to use,
you'll need a working device to plug into it. Try the 'A' first, and
if it doesn't work, switch it to 'B'. Only the W/G and W/O pairs are
being reversed. Normally, TIA 568A is used in buildings I've worked
on, but 568B is used sometimes. The TIA standard is specified when the
wiring is installed.

If it's for telephone, normally the B/W pair is used and that pair
corresponds to the R/G pair on telephone wiring. Green = Tip1 =
White/Blue, Red = Ring1 = Blue/white. The second pair on telephone is
normally Black/Yellow, so Tip2 = Black = White/Orange and Ring2 =
Yellow = Orange/White.

note: white/blue refers to a white wire with a blue stripe and
blue/white is a blue wire with a white stripe.


What are you using it for? I doubt if you're using it at 100 Mhz, so
the wiring wont be critical. If it is, the specs say no more than 3/4"
of twisted pair can be unwound at each punch-down terminal. That's the
TIA standard.