4000 Router Series Interface Configuration Guide

Configuring WAN interfaces

This chapter describes how to configure interfaces for connecting to WAN networks, including ATM and

ISDN. Available WAN interfaces include the asynchronous serial interface, synchronous serial interface,

ATM interface, ISDN BRI interface, and CE1/PRI interface.

For more information about ATM interfaces, see "Configuring ATM and DSL interfaces."

Configuring a serial interface

Overview

Asynchronous serial interface

The following types of asynchronous serial interfaces are available:

• Synchronous/asynchronous serial interface operating in asynchronous mode, whose interface

index begins with Serial.

• Dedicated asynchronous serial interface, whose interface index begins with Async.

An asynchronous serial interface can operate in flow mode or protocol mode. It can operate as a dialup

interface when having a modem or an ISDN terminal adapter (TA) attached to it. You can encapsulate

an asynchronous serial interface in protocol mode with PPP on the data link layer to provide support for

network layer protocols such as IP.

Synchronous serial interface

A synchronous serial interface has the following features:

• Operates in either DTE or DCE mode. Usually, it serves as a DTE to accept the clock provided by

DCE.

• Connected by various types of cables, such as V.24, V.35, X.21, RS449, and RS530. Your device

can automatically detect the type of connected cables and select electrical properties. In most cases,

you do not need to manually configure them.

• Supports link layer protocols such as PPP or HDLC.

• Supports network layer protocol IP.

• Provides information about the connected cable type, operating mode (DTE or DCE), and so on

after you run the display interface serial command.

Configuring an asynchronous serial interface

Configure PPP, DDR, IP address, firewall, and interface backup for the asynchronous serial interface if the

network requires.

To configure an asynchronous serial interface:

Step Command Remarks

1. Enter system view.

system-view N/A