4000 Router Series Interface Configuration Guide

Displaying and maintaining AM interfaces

Execute display commands in any view and reset commands in user view.

Task Command

Display information about the specified AM

interfaces.

display interface [ analogmodem ] [ brief [ down ] ]

display interface [ analogmodem

[ interface-number ] ] [ brief [ description ] ]

Clear statistics on a specified AM interface.

reset counters interface [ analogmodem

[ interface-number ] ]

Configuring an ISDN BRI interface

Overview

Integrated services digital network (ISDN) provides all-digital terminal-to-terminal services and fulfills the

full digitized delivery of services integrating voice, data, graphics, and video.

ISDN implements digital transmission on a user loop and provides end-to-end digitization. As a

standardized digital interface, ISDN BRI interface can forward digital and analog information.

The most commonly used ISDN standards include ITU-T I.430, Q.921, and Q.931 recommendations. All

devices that meet ITU-T ISDN standards can access an ISDN network.

ITU-T I.411 standardizes the ISDN user-network interface. It provides the referential ISDN user-network

interface configuration as shown in Figure 1 on the ba

sis of function group (a set of functions required for

accessing an ISDN network) and reference point (a concept used to differentiate function groups).

Figure 1 Referential ISDN user-network interface configuration

Function groups include:

• Network terminal 1 (NT1) implements the functionality of the first layer in the OSI reference model,

such as subscriber-line transmission, loop test, D-channel competition.

• Network terminal 2 (NT2), or named intelligent network terminal, implements the functionality of

layers 1 through 3.

• Category-1 terminal equipment (TE1), or named ISDN standard terminal, is user equipment

compliant with the ISDN interface provisions. Digital phone-set is such an example.