3Com DIGITAL MODEM manual Introduction

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1 INTRODUCTION

The Integrated Services Digital Network (ISDN) is a digital communications standard for supporting voice, data, and video applications through conventional telephone wires.

Specifically, ISDN is a method of connecting to the public telephone network using digital technology. ISDN uses the existing copper wire and public telephone network infrastructure. All existing voice services provided by the telephone companies are accessible using ISDN, and for the first time, high-speed dial-up data can be provided cost-effectively to the mass market.

Two electrical interfaces are defined as part of ISDN. The first and less expensive is Basic Rate ISDN, or 2B+D. A Basic Rate Interface (BRI) has two 56 or 64 Kbps (kilobits per second)

B(Bearer) channels for user data, and one 16 Kbps signaling D (Data) channel, used for packet communications with the public network and providing status and control information.

In most regions, the ISDN BRI is priced at 1.5 to 1.8 times the monthly cost of an analog POTS (plain old telephone service) telephone line. You may dial voice or data connections on either or both of the B channels simultaneously. Calls placed from an ISDN line may connect to remote sites that have analog POTS, Switched 56, ISDN BRI, or T1 telephone lines. There is full compatibility with existing services, and no need for ISDN BRI on both ends.

The other electrical interface, which is somewhat more expensive, is the ISDN Primary Rate Interface (PRI). PRI is based on the more expensive and higher-speed T1 networks that are typically deployed at larger sites. PRI consists of 23 B channels and one 64 Kbps D channel, providing large businesses with a greater degree of flexibility.

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Contents Member of the 3Com Impact product family Isdn External Digital Modem User Guide3Com Corporation 5400 Bayfront Plaza Santa Clara, California Contents Support from 3Com C-4 Returning Products for Repair C-4 QuickSelectFigures Tables How to Use This Guide About this GuideIntroduction Conventions Introduction Introduction 3Com Impact digital modem provides the following 3Com Impact Digital Modem FeaturesData Capabilities Voice CapabilitiesSimultaneous Data and Voice Capabilities 3Com Impact Digital Modem Package Contents 3ComA * J6 Isdn Digital Line Configuration RequirementsAT&T 5ESS Computer System RequirementsEwsd ISDN-1Apple Macintosh Requirements IBM PC or Compatible RequirementsClear to Send CTS From digital modem Ring Indicator RI Signal Ground GNDCabling Requirements DTRBack Panel Power Switch and Connectors Installing Configuring Digital ModemLED Installing the Digital Modem in an IBM-compatible PC Installing the 3Com Impact Digital ModemInstalling the Digital Modem in an Apple Macintosh Computer Installing the 3Com Impact Digital Modem Configuring the 3Com Impact Digital Modem Configuration for IBM PC or Compatible Computer Select Run from the File menu. In the Run dialog box, typeCOM port to which the digital modem is connected Installing and Configuring the Digital Modem Registers Installing and Configuring the Digital Modem Install Installing and Configuring the Digital Modem Configuration for Apple Macintosh Computer Installing and Configuring the Digital Modem Placing and Receiving Calls Placing Isdn Data CallsMultilink PPP Calls With Dynamic Bandwidth Allocation Installing and Configuring the Digital Modem Using Communications Software to Place Calls Using the Phone Out PortIncoming circuit-switched data calls from other Placing Analog Modem CallsReceiving Calls Using the Phone Out Port Placing Calls Using the Phone Out PortProtocol Support T1 access linesAsync-Sync PPP Conversion QuickSelectTroubleshooting Tips TroubleshootingTroubleshooting Monitor the B-1 and B-2 LEDs Troubleshooting Downloading Firmware to Your External Digital Modem If problems persist, refer to Appendix C,Technical SupportClick the Tools button Firmware and Tests buttons appear Click the Firmware button Firmware dialog box appearsClick OK AT Command SET OverviewAT gets the attention of your 3Com Impact digital modem Type AT Commands REGISTERS, and Result Codes AT Command Set for the 3Com Impact Digital ModemTable B-1 summarizes the AT command set SN= SN?Commands Settings AT \S\T0 disables inactivity timer default Initial configuration setATC1 AT Command Set for Internal Analog Fax ModemReceived line signal level Results of commandsNon-error corrected mode only Flow control Enable MNP mode Stream default BlockMNP extended services Mode to be negotiated in a DirectEnable inhibits MNP extended Answer mode detection phaseRemote S Registers Isdn Service provider PPP Magic-Number BlockS83 Table B-4 lists the 3Com Impact digital modem result codes Digital Modem Result Codes3Com Bulletin Board Service On-line Technical ServicesWorld Wide Web Site 3ComFacts Automated Fax ServiceAsk3Com on CompuServe To use Ask3Com Log on to CompuServeCountry Fax Number Hong Kong 852 537 Support from Your Network SupplierCountry Fax Number Italy 1678 Norway 800 Sweden 020 0800Returning Products for Repair Support from 3ComTo obtain an RMA number, call or fax Country Telephone Number Fax NumberLimited Warranty 3Com Corporation Bayfront Plaza Interference Handbook Canadian Notice

DIGITAL MODEM specifications

The 3Com Digital Modem represents a significant advancement in communication technology, designed to enhance data transmission over telephone lines. This modem is a part of a lineage of 3Com products that focus on delivering robust networking solutions, tailored for both personal and professional use.

One of the main features of the 3Com Digital Modem is its high-speed data transfer capabilities. With speeds reaching up to 56 Kbps, it allows users to send and receive large amounts of data quickly, which is essential for applications that require efficient data exchange. This speed ensures smoother internet browsing, quicker downloads, and more reliable connections for applications such as video conferencing and online gaming.

The modem is equipped with advanced error correction technologies, including V.42 and V.42bis protocols. These protocols help to maintain data integrity by detecting and correcting errors during transmission. This results in a more reliable connection, reducing the likelihood of dropped calls or corrupted data transfers, which can be particularly frustrating for users engaged in critical business communications.

Another notable characteristic of the 3Com Digital Modem is its compatibility with various operating systems, making it versatile for different users. It supports Windows, Mac, and various other platforms, ensuring that it can be integrated seamlessly into existing systems without the need for extensive configuration. This plug-and-play capability simplifies installation for users, allowing them to get connected quickly and efficiently.

The modem also incorporates an innovative design that facilitates improved heat dissipation, ensuring optimal performance during prolonged use. Its compact form factor makes it suitable for both home and office environments, allowing for easy setup without consuming excessive desk space.

In addition to these features, the 3Com Digital Modem boasts strong security protocols, ensuring that users' data is protected against unauthorized access while being transmitted. This is particularly important in today’s digital landscape, where data breaches and cyber threats are prevalent.

Overall, the 3Com Digital Modem combines speed, reliability, and security, making it a valuable asset for anyone looking to enhance their connectivity experience. Its robust feature set and user-friendly design cater to a broad audience, from casual users to business professionals, reflecting the evolution of modem technology in a digital-first world.
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