Specifications

C-4
Cisco 7100 Series VPN Router Installation and Configuration Guide
78-6341-03
Appendix C Cable Specifications
Fast Ethernet Port Cables and Pinouts
Fast Ethernet Port Cables and Pinouts
The 10BaseT/100BaseTX Fast Ethernet ports support IEEE 802.3 and IEEE 802.3u specifications for
10-Mbps and 100-Mbps transmission over unshielded twisted-pair (UTP) cables. Each Fast Ethernet
port on the router has an RJ-45 connector to attach to Category 3 or Category 5 UTP cables.
Cisco Systems does not supply Category 3 or Category 5 UTP RJ-45 cables; these cables are available
commercially.
Use a Category 3 UTP crossover cable when connecting 10BaseT port to a hub or use a Category 3 UTP
straight-through cable when connecting to an end station.
Use a Category 5 UTP crossover cable when connecting 100BaseTX to a hub or use a Category 5 UTP
straight-through cable when connecting to an end station.
To determine the type of RJ-45 cable, examine the sequence of colored wires as follows:
• Straight-through—Colored wires are in the same sequence at both ends of the cable.
• Crossover—The first (far left) colored wire at one end of the cable is the third colored wire at the
other end of the cable, and the second colored wire at one end of the cable is the sixth colored wire
at the other end of the cable.
Table C-4 lists the 10BaseT pinouts and Table C-5 lists the 100BaseTX pinouts for the two Fast Ethernet
ports.
Table C-4 10BaseT RJ-45 Connector Pinouts
RJ-45 Pin Description
1Tx+
2Tx–
3Rx+
6Rx–
Table C-5 100BaseTX RJ-45 Connector Pinouts
RJ-45 Pin Description
1Tx+
2Tx–
3Rx+
6Rx–