HP J3245A Installation And Configuration Manual page 166

Cables and Connectors
Twisted-Pair Cable/Connector Pin-Outs
Twisted-Pair Cable from Switch-Based MDI-X Module to an
MDI-X Hub Port
To connect an MDI-X port on a hub to the Switch 800T, use a "crossover" cable.
The twisted-pair wires must be twisted through the entire length of the cable.
The wiring sequence must conform to AT&T 258A (not USOC). See "Twisted-
Pair Cable Pin Assignments" on page A-5 for a listing of the signals used on
each pin.
N o t e
Pins 1 and 2 on connector "A" must be wired as a twisted pair to pins 3 and 6
on connector "B".
Pins 3 and 6 on connector "A" must be wired as a twisted pair to pins 1 and 2
on connector "B".
Pins 4, 5, 7, and 8 are not used in this application, although they may be wired
in the cable.
A-4