Overview
Ethernet has been the most successful LAN technology largely because of its simplicity of implementation compared to other technologies. Ethernet has also been successful because it has been a flexible technology that has evolved to meet changing needs and media capabilities. This module introduces the specifics of the most important varieties of Ethernet. The goal is not to convey all the facts about each type of Ethernet, but rather to develop a sense of what is common to all forms of Ethernet.

Changes in Ethernet have resulted in major improvements over the 10-Mbps Ethernet of the early 1980s. The 10-Mbps Ethernet standard remained virtually unchanged until 1995 when IEEE announced a standard for a 100 Mbps Fast Ethernet. In recent years, an even more rapid growth in media speed has moved the transition from Fast Ethernet to Gigabit Ethernet. The standards for Gigabit Ethernet emerged in only three years. An even faster Ethernet version, 10 Gigabit Ethernet, is now widely available and still faster versions are being developed.

In these faster versions of Ethernet, MAC addressing, CSMA/CD, and the frame format have not been changed from earlier versions of Ethernet. However, other aspects of the MAC sublayer, physical layer, and medium have changed. Copper-based network interface card (NICs) capable of 10/100/1000 operation are now common. Gigabit switch and router ports are becoming the standard for wiring closets. Optical fiber to support Gigabit Ethernet is considered a standard for backbone cabling in most new installations.

Students completing this module should be able to:

  • Describe the differences and similarities among 10BASE5, 10BASE2, and 10BASE-T Ethernet.
  • Define Manchester encoding.
  • List the factors affecting Ethernet timing limits.
  • List 10BASE-T wiring parameters.
  • Describe the key characteristics and varieties of 100-Mbps Ethernet.
  • Describe the evolution of Ethernet.
  • Explain the MAC methods, frame formats, and transmission process of Gigabit Ethernet.
  • Describe the uses of specific media and encoding with Gigabit Ethernet.
  • Identify the pinouts and wiring typical to the various implementations of Gigabit Ethernet.
  • Describe the similarities and differences between Gigabit and 10 Gigabit Ethernet.
  • Describe the basic architectural considerations of Gigabit and 10 Gigabit Ethernet.