Table of Contents

Connectors and Cable Specifications

Connectors and Cable Specifications

This appendix describes the Catalyst 2900 XL switch ports and the cables and adapters that you use to connect the switch to other devices.

Connector Specifications

10/100 Ports

The 10/100 Ethernet ports use standard RJ-45 connectors and Ethernet pinouts with internal crossovers, as shown by an X in the port name. These ports have their transmit (TD) and receive (RD) signals internally crossed so that a straight-through cable and an adapter can be attached to the port. Figure B-1 shows the pinouts.

When connecting the 10/100 ports to compatible workstations, servers, routers, and Cisco IP Phones, you must use a straight-through cable wired for 10BASE-T and 100BASE-TX. (Figure B-4 shows the straight-through cable schematics.) When connecting to other switches or repeaters, you must use a crossover cable. (Figure B-5 shows the crossover cable schematics.)

Note   Use a straight-through cable to connect two ports when one of the ports is designated with an X. Use a crossover cable to connect two ports when both connectors and cables are designated with an X or when both ports do not have an X.

100BASE-FX Ports

100BASE-FX ports use duplex SC connectors, as shown in Figure B-2. These ports use 10/125- or 62.5/125-micron multimode fiber-optic cabling.

LRE Ports

The LRE ports use a single RJ-21 connector, as shown in Figure B-3.

Figure B-3: RJ-21
Connector

Console Port

The console port uses an 8-pin RJ-45 connector, described in Table B-2 and Table B-3. The supplied RJ-45-to-RJ-45 rollover cable and DB-9 adapter are used to connect the console port of the switch to a console PC. You need to provide a RJ-45-to-DB-25 female DTE adapter if you want to connect the switch console port to a terminal. You can order a kit (part number ACS-DSBUASYN=) containing that adapter from Cisco. For console port and adapter pinout information, see Table B-2 and Table B-3.

Cable and Adapter Specifications

Crossover and Straight-Through Cable Pinouts

The schematics of crossover and straight-through cables are shown in Figure B-4 and Figure B-5.

RJ-21 Cable Pinouts

Note   Table B-1 shows the pinouts for the RJ-21 connector on a Catalyst 2924 LRE XL switch. On a Catalyst 2912 LRE XL switch, only circuits 1 to 12 are valid.

Console Port

The console port uses an 8-pin RJ-45 connector, as shown in Figure B-7 and described in Table B-2. The supplied RJ-45-to-RJ-45 rollover cable and adapters connect the console port of the switch to a console PC or terminal. The following sections describe the rollover cable and adapters for the console port.

Identifying a Rollover Cable

You can identify a rollover cable by comparing the two modular ends of the cable. Hold the cable ends side-by-side, with the tab at the back. The wire connected to the pin on the outside of the left plug should be the same color as the wire connected to the pin on the outside of the right plug (see Figure B-6).

Connecting to a PC

Use the thin, flat, RJ-45-to-RJ-45 rollover cable and RJ-45-to-DB-9 female DTE adapter (both provided) to connect the console port to a PC running terminal-emulation software. Figure B-7 shows how to connect the console port to a PC. Table B-2 lists the pinouts for the console port, the RJ-45-to-RJ-45 rollover cable, and the RJ-45-to-DB-9 female DTE adapter.

Connecting to a Terminal

Use the thin, flat, RJ-45-to-RJ-45 rollover cable and RJ-45-to-DB-25 female DTE adapter to connect the console port to a terminal. Table B-3 lists the pinouts for the console port, the RJ-45-to-RJ-45 rollover cable, and the RJ-45-to-DB-25 female DTE adapter.

Note   The RJ-45-to-DB-25 female DTE adapter is not supplied with the switch. You can order a kit (part number ACS-DSBUASYN=) containing this adapter from Cisco.