Cisco Systems 3550 manual Cable and Adapter Specifications, Two Twisted-Pair Cable Pinouts

Appendix B Connector and Cable Specifications

Cable and Adapter Specifications

Cable and Adapter Specifications

These sections describe the cables and adapters used with the Catalyst 3550 switches.

Two Twisted-Pair Cable Pinouts

Figure B-4and Figure B-5show the schematics of two twisted-pair cables for ports running 10 Mbps traffic.

Figure B-4 Two Twisted-Pair Straight-Through Cable Schematic

Switch

3TD+

6 TD–

1RD+

2 RD–

Router or PC

3 RD+ 6 RD–

1 TD+	H5578
2 TD–

Figure B-5 Two Twisted-Pair Crossover Cable Schematic

Switch	Switch
3 TD+	3 TD+
6 TD–	6 TD–
1 RD+	1 RD+
2 RD–	2 RD–

H5579

Four Twisted-Pair Cable Pinouts for 10/100 Ports

Figure B-6and Figure B-7show the schematics of four twisted-pair cables for ports running 10 or 100 Mbps traffic.

For inline power connections, signal pairs are used to provide inline power. Nominally, there is 48 V between the pin pairs (1–2), and pairs (3–6) when inline power is active.

Figure B-6

Switch

1 RD+

2 RD-

3TD+

6TD-

4NC

5NC

7NC

8NC

Four Twisted-Pair Straight-Through Cable Schematic for 10/100 Ports

Router or PC

1TD+

2TD-

3RD+

6RD-

4	NC
5	NC
7	NC	65271
8	NC

Catalyst 3550 Multilayer Switch Hardware Installation Guide

OL-6155-01 B-3