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.
|