7 Fax Operation

The U-336S/SA can be used as a fax machine. In the sections below, we will describe how the modem works as a fax machine, the ITU-T T.30 fax protocol, the Class 1,2, and 2.0 fax commands and ZyXEL extended fax AT commands. Also covered are the status report result codes, the flow control protocol associated with ZyXEL fax AT commands, and some specific fax applications. The instructions for using the included modem/fax/voice utility program are included on the software disk. Some distributors and dealers may have included other software with your modem. For help with such software, refer to the software instructions.

Fax Basics

Fax is the abbreviation for facsimile. There are four major parts in a fax machine: the scanner, encoding and decoding device, modem, and printer. Before a page can be sent, it is first scanned. The bit-mapped data is encoded with data compression and is then transmitted across the phone line by an internal modem module. The remote facsimile receives the data with its internal modem, decodes it back to bit- mapped image data, and prints it on paper.

Fax Branding: The Telephone Consumer Protection Act of 1991 makes it unlawful for any person to use a computer or other electronic device to send any message via a telephone or fax machine unless such message clearly contains in a margin at the top or bottom of each transmitted page or on the first page of the transmission, the date and time it is sent and an identification of the business or other entity, or individual sending the message and the telephone number of the sending

64 Fax Operation

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ZyXEL Communications U-336SA user manual Fax Operation, Fax Basics

U-336S, U-336SA specifications

ZyXEL Communications, a leading global provider of networking and cybersecurity solutions, has offered a range of products designed to cater to various connectivity needs. Among these, the U-336SA and U-336S modems stand out for their reliability and performance, particularly in the dial-up category during the heyday of internet access.

The U-336SA and U-336S modems are external devices that revolutionized the way users connected to the internet in the late 1990s and early 2000s. Designed for both home users and small businesses, these modems supported 33.6 Kbps data transfer rates, which, at the time, were considered cutting-edge. This capability allowed for reasonably swift internet browsing, email communication, and file downloads compared to earlier modems.

One notable feature of both the U-336SA and U-336S models is their plug-and-play functionality. This ease of use made them accessible to even the less tech-savvy users, allowing quick and straightforward installation. Users could connect the modems to their PCs or laptops via a standard serial interface, minimizing setup time and complexity.

Additionally, both modems were equipped with error correction and data compression technologies. The V.42 and V.42bis protocols enhanced data integrity during transmission, ensuring that users experienced fewer disruptions and greater reliability in their connecting experience. This was particularly vital for tasks like file transfers and large downloads, where data integrity was paramount.

The modems also featured compatibility with various operating systems, including early versions of Windows, which expanded their appeal to a broader audience. The U-336SA was specifically engineered as a standalone device, while the U-336S could often be used with existing computer systems, showcasing versatility in various deployment scenarios.

In terms of design, both modems were compact and lightweight, allowing for easy portability. This made them suitable for users who required connectivity on the go or in different locations.

Ultimately, the ZyXEL U-336SA and U-336S modems represent a significant technological achievement in the history of internet connectivity. Their introduction set the stage for subsequent advancements in modem technology and played a crucial role in the evolution towards broadband and high-speed internet access that we enjoy today. Their legacy endures in the foundational technologies and protocols that continue to drive modern telecommunications.