Cisco C9550 Series Smart Switches Hardware Installation Guide

Cables and adapters

Updated: July 17, 2026

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Provides information about the various types of cables and adapters for supporting transceivers.

This section provides information about the transceiver module network cables, cable pinouts, and console port adapter pinouts.

Transceiver module network cables

For transceiver module installation notes, refer to

Each port must match the wavelength specifications on the other end of the cable, and the cable must not exceed the stipulated cable length. Copper 1000BASE-T SFP module transceivers use standard four twisted-pair, Category 5 cable at lengths up to 328 feet (100 meters).

Cable pinouts

A cable pinout refers to the specific arrangement of wires within a cable connector. Pinouts define how each pin is connected between the two ends of a cable.

Figure 1. Four twisted-pair straight-through cable schematic

Figure 2. Four twisted-pair semi-cross cable schematic

Figure 3. Two twisted-pair straight-through cable schematic

Figure 4. Two twisted-pair crossover cable schematic

Identifying a crossover cable

To identify a crossover cable, compare 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 a different color from the wire connected to the pin on the inside of the right plug.

Console port adapter pinouts

Use an RJ-45-to-DB-9 adapter cable to connect the switch console port to a console PC. You need to provide a RJ-45-to-DB-25 female DTE adapter to connect the switch console port to a terminal.

Table 1. Console port signaling with a DB-9 adapter
Switch console port (DTE)	RJ-45-to-DB-9 terminal adapter	Console device
Signal	DB-9 Pin	Signal
TxD	2	RxD
GND	5	GND
GND	5	GND
RxD	3	TxD

Table 2. Console port signaling with a DB-25 adapter
Switch console port (DTE)	RJ-45-to-DB-25 terminal adapter	Console device
Signal	DB-25 pin	Signal
TxD	3	RxD
GND	7	GND
GND	7	GND
RxD	2	TxD

The following table summarizes the ToD/1-PPS port pinouts.

Table 3. ToD pinouts
Pin	Signal Name	Direction	Description
1	RESERVED	Output or input	Do Not connect
2	RESERVED	Output or input	Do Not connect
3	1PPS_N	Output	1PPS RS422 signal
4	GND	—	—
5	GND	—	—
6	1PPS_P	Input	1PPS RS422 signal
7	TOD_N	Output or input	Time-of-Day R422 output or input signal
8	TOD_P	Output or input	Time-of-Day R422 output or input signal

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