3Com DIGITAL MODEM manual Introduction

1-2 CHAPTER 1: INTRODUCTION

The 3Com Impact ISDN External Digital Modem (referred to as the 3Com Impact digital modem throughout this guide) is an external, stand-alone ISDN Basic Rate digital modem for connection with digital telephone services from local telephone companies in North America. It is designed for users who require high-speed access to the Internet, on-line information services, or their corporate local area network (LAN). A typical 3Com Impact digital modem application is shown in Figure 1-1.

3Com Impact

ISDN External

Digital Modem

3ComImpact

ISDN line

Public telephone

network

Analog or ISDN line

Internet

or

on-line service

Analog or ISDN line

Corporate

LAN

Figure 1-1 Analog and Digital Network Access with the 3Com Impact Digital Modem

Four models of the 3Com Impact digital modem are sold in the U.S. and Canada:

■3C871 is the IBMâ or IBM-compatible PC external digital modem product.

■3C872 is the IBM or IBM-compatible PC external digital modem product with an internal 14.4 Kbps analog fax modem.

■3C876 is the Appleâ Macintoshâ external digital modem product.

■3C877 is the Apple Macintosh external digital modem product with an internal 14.4 Kbps analog fax modem.