2-16 CHAPTER 2: INSTALLING AND CONFIGURING THE DIGITAL MODEM

By default, the 3Com Impact digital modem dials the same number for both Multilink PPP channels. If the destination to which the digital modem is dialing to establish a second Multilink PPP channel requires a different telephone number, then this second telephone number is stored in register S81. By default, this register is empty. It must be configured before you establish each Multilink PPP call. If the Multilink PPP destination is a single telephone number for both channels, then be sure to clear register S81 by sending the command ATS81=<blank> to the digital modem.

Some Multilink PPP implementations require the use of a Multilink PPP option called the Multilink Endpoint Identifier. This option is configured in registers S82 and S83.

Register S82 stores the Multilink Endpoint Identifier Class value. Valid classes are listed in Appendix B,“AT Commands, Registers, and Result Codes.” Register S83 stores the actual Multilink Endpoint Identifier. Note that this option is not required in most cases, so these registers typically do not have to be changed. If the Multilink Endpoint Identifier is required, these values will be provided by your system administrator or Internet service provider.

When dynamic bandwidth allocation is enabled (by default), you can place a voice call from a device that is attached to the Phone Out port while a Multilink PPP call is active. When you lift the telephone handset to place a voice call, the digital modem automatically removes one of the Multilink

PPPconnections and uses it for the voice call. Once the voice call ends, the digital modem automatically reestablishes that channel for Multilink PPP operation.

There may be cost implications due to the use of two B channels for Multilink PPP. Check with your service providers, such as the telephone company, Internet access provider, or on-line service provider.

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3Com DIGITAL MODEM manual Installing and Configuring the Digital Modem

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.