# SRP I/O Module

The SRP I/O module provides two management ports. You can connect a console directly to the RS-232 serial port using a shielded straight-through cable with a female DB-9 connector on one end and a male DB-25 with a crossover adapter on the DB-25 end. This port is called the serial port, the RS-232 port, or the console serial port. Figure 54 shows the location of the serial port and the sequence of the pins in the RS-232 connector.

The console port is considered a data terminal equipment interface (DTE). Direct connection to a terminal or PC (which also have DTE interfaces) requires a crossover cable.

Figure 54: SRP I/O Module Serial Port

Table 18 lists the pinout for the serial cable's RS-232 connector.

Table 18: SRP I/O Module—RS-232 Serial Connector Pinout

Pin | Signal
--- | ---
1 | DCD
2 | RXD
3 | TXD
4 | DTR
5 | GND
6 | DSR
7 | RTS
8 | CTS
9 | RNG

After you have configured an IP address on the system, you can connect using a host running Telnet over the 10/100Base-T Ethernet port on the SRP I/O module. The router ships with a straight-through cable having a male RJ-45 Ethernet connector on each end. Figure 55 shows the location of the Ethernet port and the sequence of the pins in the RJ-45 connector.

Figure 55: SRP I/O Module Ethernet Port

Table 19 lists the pinouts for the Ethernet cable's RJ-45 connector.

Table 19: SRP I/O Module—RJ-45 Connector Pinout

Pin | Signal
--- | ---
1 | TX +
2 | TX –
3 | RX +
4 | no connect
5 | no connect
6 | RX –
7 | no connect
8 | no connect

To facilitate connecting the system to a terminal, the system is shipped with one of each of the following cable adapters:

- DB-9 female to RJ-45 female crossover null modem adapter
- DB-9 female to RJ-45 female straight-through adapter

Table 20 lists the pinouts for the crossover adapter.

Table 20: DB-9—RJ-45 Crossover Adapter Pinout

DB-9 Pin | Signal | RJ-45 Pin
--- | --- | ---
1 | DCD | 1
2 | RXD | 3
3 | TXD | 2
4 | DTR | 6
5 | GND | 5
6 | DSR | 4
7 | RTS | 8
8 | CTS | 7
9 | RNG | no connect

Table 21 lists the pinout for the straight-through adapter.

Table 21: DB-9—RJ-45 Straight-Through Adapter Pinout

DB-9 Pin | RS-232 Signal Name | RJ-45 Pin | Ethernet Signal Name
--- | --- | --- | ---
1 | DCD | 1 | TX +
2 | RXD | 2 | TX –
3 | TXD | 3 | RX +
4 | DTR | 4 | no connect
5 | GND (signal) | 5 | no connect
6 | DSR | 6 | RX –
7 | RTS | 7 | no connect
8 | CTS | 8 | no connect
9 | RNG | no connect | none