Configuring Wan Interfaces; Configuring A Serial Interface; Asynchronous Serial Interface; Synchronous Serial Interface - HP MSR Router Series Configuration Manual

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 interfaces."

Configuring a serial interface

Asynchronous serial interface

The following types of asynchronous serial interfaces are available:
• Synchronous/asynchronous serial interface operating in asynchronous mode. The interface type
name is Serial.
Dedicated asynchronous serial interface. The interface type name is Async.
•
You can connect a modem or ISDN terminal adapter to an asynchronous serial interface for dial-up
connection.
An asynchronous serial interface can operate in protocol or flow mode.
• Protocol mode—Data is transmitted in packets. The link layer protocol can only be PPP. The network
layer protocol is typically IP.
Flow mode—Data is transmitted as character flows. This mode is typically used in human-machine
•
interaction scenarios such as dial-up access. After the physical connection is established, you can
send commands to set up a link with the asynchronous serial interface, and then configure the
device.

Synchronous serial interface

Synchronous serial interfaces refer to synchronous/asynchronous serial interfaces operating in
synchronous mode. They provide serial communication channels for synchronous data transmission. The
interface type name is Serial.
A synchronous serial interface operates in DCE or DTE mode. Two directly connected synchronous serial
interfaces must operate in different modes.
In DCE mode, the interface provides timing for synchronization and sets the baud rate.
•
In DTE mode, the interface accepts the timing signal and baud rate from the DCE.
•
The synchronous serial interfaces on the device are typically operating as DTE.
A synchronous interface can be connected to various types of cables, including V.24, V.35, X.21, RS449,
and RS530. Typically, the device can automatically recognize the cable type and select electrical
properties.
The synchronous serial interface supports multiple data link layer protocols, including PPP and HDLC. The
interface supports IP at the network layer.
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