Electromagnetic Compatibility

ELECTROMAGNETIC COMPATIBILITY

FCC STATEMENT

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules, and the Canadian Department of Communications Equipment Standards entitled, “Digital Apparatus,” ICES-003. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation.

If this equipment does cause interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

■Reorient the receiving antenna.

■Relocate the equipment with respect to the receiver.

■Move the equipment away from the receiver.

■Plug the equipment into a different outlet so that equipment and receiver are on different branch circuits.

■Consult the dealer or an experienced radio/television technician for help.

CSA STATEMENT

This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations.

Cet appareil numérique de la classe B respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada.

VCCI STATEMENT

BCIQ STATEMENT

INFORMATION TO THE USER

The user may find the following booklet prepared by the Federal Communications Commission helpful:

How to Identify and Resolve Radio-TV Interference Problems

This booklet is available from the U.S. Government Printing Office, Washington, DC 20402, Stock No. 004-000-00345-4.

In order to meet FCC emissions limits, this equipment must be used only with cables which comply with IEEE 802.3.

Hub specifications

3Com Hub: A Cornerstone of Early Networking Technology

The 3Com Hub represents one of the pioneering devices in the realm of computer networking. Developed by 3Com Corporation in the late 1980s, it played a significant role in facilitating communication within local area networks (LANs). As an essential component during the rise of networked computing, the 3Com Hub laid the groundwork for the development of more advanced networking technologies that followed.

One of the main features of the 3Com Hub is its ability to connect multiple devices within a network in a straightforward manner. Operating primarily at the data link layer (Layer 2) of the OSI model, the hub allows for the interconnection of computers, printers, and other network devices using twisted-pair Ethernet cables. Typically available in 8, 16, or 24 ports, it offered scalability to organizations as they expanded their networks.

The hub operates using Ethernet technology, which was evolving rapidly at the time. It effectively transmitted data packets by broadcasting signals to all connected devices. While this method is simple and efficient for smaller networks, it also means that bandwidth is shared among all devices. This mechanism could lead to collisions when multiple devices attempted to send data simultaneously, a common limitation during the era of hubs.

In terms of characteristics, the 3Com Hub is a plug-and-play device, meaning it requires no complex configuration. This ease of installation was particularly advantageous for organizations that were just beginning to adopt networking technologies. The hub also supported a variety of Ethernet standards, including 10BASE-T and 100BASE-T, allowing for flexible implementation as network requirements evolved.

3Com hubs were designed with durability in mind, with a robust chassis that could withstand the rigors of office environments. They typically featured LED indicators for power and link status, providing users with immediate feedback about the operation of the network. Although modern networking has moved toward switches and routers that provide greater efficiency and intelligence, the 3Com Hub remains an iconic representation of early networking solutions.

In conclusion, the 3Com Hub played a vital role during the formative years of computer networking, providing the foundation for many of the technologies that dominate today’s networks. While it may seem primitive in the context of advanced networking options available today, its influence on the development of LAN technologies is undeniable. As organizations continue to navigate the evolution of networking, the legacy of the 3Com Hub endures.