3Com DIGITAL MODEM manual Troubleshooting

Page 38

3-2 CHAPTER 3: TROUBLESHOOTING

The 3Com Impact digital modem will not operate if connected to an analog telephone wall jack. Make sure that the digital modem is connected directly into the ISDN wall outlet without connection to any intermediate telephone equipment (an NT1 device is not required with this digital modem).

4Make sure that the cables provided by 3Com or a 3Com authorized reseller are in good condition and show no evidence of wear or other physical damage.

If damage is apparent after close inspection, contact your reseller for replacement cables.

5Monitor the status of the D channel LED.

■If you are connected to a live digital ISDN line, the

D channel LED remains lit for up to a few minutes after the self-test but then begins to flash.

When the D channel LED flashes, it indicates that the ISDN signal is present.

When the D channel LED goes out, it indicates that a valid communication channel has been established and calls may be attempted by the user.

■If the D channel LED remains lit after more than a few minutes, it is likely that there is a poor physical connection to the local telephone company.

This fault can be caused by a damaged cable, a broken wire, a damaged connector, a nonstandard U interface (proprietary AMI line coding), or a problem within the telephone company network. If the telephone wires at your site appear to be satisfactory, call your local telephone company for repair of telephone company equipment and troubleshooting assistance.

■If the D channel LED flashes for more than a few minutes without going out, there is probably a mismatch between the settings of the ISDN line and the 3Com Impact digital modem configuration.

Page 37 Page 39
Image 38
Page 37 Page 39
Contents Isdn External Digital Modem User Guide Member of the 3Com Impact product family3Com Corporation 5400 Bayfront Plaza Santa Clara, California Contents QuickSelect Support from 3Com C-4 Returning Products for Repair C-4Figures Tables Introduction How to Use This GuideAbout this Guide Conventions Introduction Introduction 3Com Impact Digital Modem Features 3Com Impact digital modem provides the followingSimultaneous Data and Voice Capabilities Data CapabilitiesVoice Capabilities 3Com Impact Digital Modem Package Contents Isdn Digital Line Configuration Requirements 3ComA * J6Ewsd Computer System RequirementsAT&T 5ESS ISDN-1IBM PC or Compatible Requirements Apple Macintosh RequirementsCabling Requirements Signal Ground GNDClear to Send CTS From digital modem Ring Indicator RI DTRInstalling Configuring Digital Modem Back Panel Power Switch and ConnectorsLED Installing the 3Com Impact Digital Modem Installing the Digital Modem in an IBM-compatible PCInstalling the Digital Modem in an Apple Macintosh Computer Installing the 3Com Impact Digital Modem Configuring the 3Com Impact Digital Modem COM port to which the digital modem is connected Configuration for IBM PC or Compatible ComputerSelect Run from the File menu. In the Run dialog box, type 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 Multilink PPP Calls With Dynamic Bandwidth Allocation Placing and Receiving CallsPlacing Isdn Data Calls Installing and Configuring the Digital Modem Incoming circuit-switched data calls from other Using the Phone Out PortUsing Communications Software to Place Calls Placing Analog Modem CallsPlacing Calls Using the Phone Out Port Receiving Calls Using the Phone Out PortAsync-Sync PPP Conversion T1 access linesProtocol Support QuickSelectTroubleshooting Troubleshooting TipsTroubleshooting Monitor the B-1 and B-2 LEDs Troubleshooting Click the Tools button Firmware and Tests buttons appear If problems persist, refer to Appendix C,Technical SupportDownloading Firmware to Your External Digital Modem Click the Firmware button Firmware dialog box appearsClick OK AT gets the attention of your 3Com Impact digital modem AT Command SETOverview Type Table B-1 summarizes the AT command set AT Commands REGISTERS, and Result CodesAT Command Set for the 3Com Impact Digital Modem SN? SN=\T0 disables inactivity timer default Settings AT \SCommands Initial configuration setAT Command Set for Internal Analog Fax Modem ATC1Non-error corrected mode only Results of commandsReceived line signal level Flow control Enable MNP mode Stream default BlockEnable inhibits MNP extended Mode to be negotiated in a DirectMNP extended services Answer mode detection phaseRemote S Registers Isdn S83 Service providerPPP Magic-Number Block Digital Modem Result Codes Table B-4 lists the 3Com Impact digital modem result codesOn-line Technical Services 3Com Bulletin Board ServiceAsk3Com on CompuServe 3ComFacts Automated Fax ServiceWorld Wide Web Site To use Ask3Com Log on to CompuServeCountry Fax Number Italy 1678 Support from Your Network SupplierCountry Fax Number Hong Kong 852 537 Norway 800 Sweden 020 0800To obtain an RMA number, call or fax Support from 3ComReturning Products for Repair 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.
Top Page Image Contents