Crossover Wiring; B.3.1 Crossover Wiring - Cabletron Systems 3E02-04 User Manual

Appendix B: Cables
Table B-7 RJ45 Crossover Pin Assignments
*The "+" and "–" signs are used to represent the polarity
of the two wires that make up each wire pair.
B.3.1

Crossover Wiring

Two Ethernet 10BASE-T devices can communicate only if the transmitter
on one device is connected to the receiver on the other device. This
reversal, or crossover function, can be implemented either in the wiring or
in the device itself.
When connecting two identical UTP ports (i.e., both crossover ports or
both straight-through ports), a crossover must be implemented in the
wiring. Refer to the following table for crossover pin assignments.
Table B-8 Crossover - RJ45 Pin Assignments
Page B-4
RJ45 Pin
1
2
3
6
Hub
1 (Tx+)
2 (Tx–)
3 (Rx+)
6 (Rx–)
Ethernet Switch Module User Guide
*
Assignment
Tx+
Tx–
Rx+
Rx–
Device
3 (Rx+)
6 (Rx–)
1 (Tx+)
2 (Tx–)