10Base-T/100Base-Tx Pin Assignments - SMC Networks SMC7800A Installation Manual

C
ABLES

10BASE-T/100BASE-TX Pin Assignments

Use unshielded twisted-pair (UTP) or shielded twisted-pair (STP) cable for
RJ-45 connections: 100-ohm Category 3, 4 or 5 cable for 10 Mbps
connections, or 100-ohm Category 5 cable for 100 Mbps connections.
Also be sure that the length of any twisted-pair connection does not
exceed 100 meters (328 feet).
The RJ-45 ports on the CPE support automatic MDI/MDI-X operation,
so you can use straight-through cables for all network connections to PCs
or gateways. In straight-through cable, pins 1, 2, 3, and 6, at one end of the
cable, are connected straight through to pins 1, 2, 3, and 6 at the other end
of the cable. When using the RJ-45 port on this CPE, you can use either
straight-through or crossover cable.
Table B-1 10/100BASE-TX MDI and MDI-X Port Pinouts
Pin
1
2
3
6
4,5,7,8
Note: The "+" and "-" signs represent the polarity of the wires that
make up each wire pair.
B-2
MDI Signal Name
Transmit Data plus (TD+)
Transmit Data minus (TD-)
Receive Data plus (RD+)
Receive Data minus (RD-)
Not used
MDI-X Signal Name
Receive Data plus (RD+)
Receive Data minus (RD-)
Transmit Data plus (TD+)
Transmit Data minus (TD-)
Not used