10Base-T Pin Assignments - Cabletron Systems 3E02-04 User Manual

B.3 10BASE-T PIN ASSIGNMENTS
An Ethernet cable link requires the use of two pairs of a multi-pair cable.
While a cable containing only two pairs of wire can be used, it is more
common to use four-pair cabling for 10BASE-T links. The jacket of each
wire in a four-pair cable will have an overall color; brown, blue, orange,
green, or white. In a 4-pair UTP cable (the typical UTP used in
networking installations) there will be one wire each of brown, blue,
green, and orange, and four wires whose overall color is white. The white
wires will be distinguished from one another by periodically placed
(usually within 1/2 inch of one another) rings of the other four colors.
Each wire pair must be attached to the RJ45 connectors in a
NOTE
certain orientation. (See Table B-7 for an explanation.)
Refer to the diagram below and note how the pins are numbered. Be sure
to hold the connectors in the same orientation when connecting the wires
to the pins.
1 2 3 4 5 6 7 8
TX+
TX-
Each UTP link segment must have an RJ45 male connector attached to
both ends. According to the 10BASE-T specification, pins 1 and 2 on the
RJ45 connector are used for transmitting data; pins 3 and 6 are used for
receiving data, as shown below.
Ethernet Switch Module User Guide
RX-
RX+
Figure B-1 RJ45 Connector Pin Numbers

10BASE-T Pin Assignments

1
8
1
8
Page B-3