# Cabling the SRP IOA

Before powering up the router, you must set up a management console. The console enables you to communicate with your system during the power-up process and to manage your system using the command-line interface (CLI).

When connecting a console directly to the SRP IOA, use a cable appropriate for your terminal connector. The cable must have a female DB-9 connector to attach to the RS-232 port on the SRP IOA. See Figure 26.

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.

The router has network timing ports and management ports located on the SRP IOA. See Figure 26 and Table 7 for details on each component.

Table 7: SRP IOA Ports

Port | Description
--- | ---
Network timing ports | Two dual-purpose BNC connectors for BITS timing clock sources (E1 or T1) User-configurable through the CLI Primary (A) and secondary (B) 75-ohm E1 2.048-Mbps/T1 1.544–Mbps inputs terminating with a 120/75 ohm or 100/75 ohm balun
Management ports | One 10/100Base-T Ethernet management port with an RJ-45 connector Two RS-232 ports with a DB-9 connector for direct CLI (Console) and debug (Auxiliary) access. The Auxiliary port is used to debug ports on a specific processor (SRP module, LM).

## Network Timing Ports

The SRP IOA has two input ports for external network clock sources (75-ohm E1 2.048-Mbps/T1 1.544–Mbps inputs with BNC connectors). These ports provide a way to ensure that the router system clock remains synchronized with the network's system clock. The primary clock is labeled A; the secondary, redundant clock, is labeled B. See Figure 26.

| Note: We recommend you use shielded cables to connect the external clock sources to the clock source input ports. Shielded cables are not required for the operation of the system and do not need to be grounded at both ends.

Figure 26: SRP IOA

To connect the clock source input ports:

1. Attach the BNC connector to Clock A's network timing port.
2. Attach the opposite end of the network timing cable to your network's clock source A.
3. Repeat steps 1 and 2 for the Clock B connections.

## Management Ports

The Management section of the SRP IOA has three ports (Figure 26) for management access:

- One 10/100Base-T Ethernet port—Accepts an RJ-45 (male) connector, providing an out-of-band connection for LAN access through a Telnet session or SNMP.
- Two RS-232 management ports—Accept a DB-9 (female) connector. One port provides direct CLI access from a console terminal; the other Auxiliary port provides debug access from a console terminal.

The management 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.

See Accessing E Series Routers for more information about management access.

### Connecting to the Network

To connect the router to the network:

1. Insert an Ethernet cable (RJ-45) connector into the 10/100Base-T (RJ-45) port on the SRP IOA until it clicks into place.
2. Connect the other end of the cable to the appropriate Ethernet network for an out-of-band connection.

### Connecting to a Console Terminal

When you connect a console directly to the SRP IOA, use a cable appropriate for your terminal connector. The cable must have a female DB-9 connector to attach to the RS-232 port on the SRP IOA.

To connect the console to the SRP IOA:

1. Insert the female DB-9 connector into the RS-232 port, and tighten the screws.

   | Caution: Do not overtighten the screws.

2. Connect the other end of the cable to your terminal's serial port (VT100/ANSI).