Serial Interface Overview; Serial Interface Features Supported By The Ar1200; Configuring A Synchronous Serial Interface; Establishing The Configuration Task - Huawei AR1200 series Configuration Manual

Huawei AR1200 Series Enterprise Routers
Configuration Guide - Interface Management

4.1 Serial Interface Overview

This section describes the types and functions of serial interfaces.
Serial interfaces are WAN interfaces and work in synchronous or asynchronous mode.
When a serial interface is used to establish a Digital Data Network (DDN) leased line or connects
to a terminal, the interface works in synchronous mode. When a serial interface is used to
establish an asynchronous leased line or is used for modem dial-up, data backup, or terminal
access, the interface works in asynchronous mode.

4.2 Serial Interface Features Supported by the AR1200

This section describes the serial interface features supported by the AR1200.
Serial interfaces on the AR1200 work in synchronous or asynchronous mode.
Synchronous serial interfaces have the following features:
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An asynchronous serial interface works in either protocol or flow mode:
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4.3 Configuring a Synchronous Serial Interface

Configuring a synchronous serial interface includes setting physical and link layer parameters.

4.3.1 Establishing the Configuration Task

Before configuring a synchronous serial interface, familiarize yourself with the applicable
environment, complete the pre-configuration tasks, and obtain the data required for the
configuration. This will help you complete the configuration task quickly and accurately.
Issue 01 (2012-04-20)
Synchronous serial interfaces on two ends of a cable play different roles. One interface
functions as a Data Terminal Equipment (DTE) interface, and the other functions as a Data
Circuit-terminating Equipment (DCE) interface. The AR1200 functions as a DTE or DCE.
Link layer protocols include the Point-to-Point Protocol (PPP), Frame Relay (FR), and
High-Level Data Link Control (HDLC).
The network layer protocol is the Internet Protocol (IP).
Protocol mode
– Serial interfaces on both ends establish a link based on the existing link layer protocol
parameters after a physical connection is established between them.
– The link layer protocol is PPP, and the network layer protocol is IP.
Flow mode
– The local interface sends physical layer protocol parameters to the remote interface, and
then the two interfaces establish a link based on the configured parameters.
– The link layer protocol and network layer protocol (IP) are not supported.
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