Module 7: Ethernet Technologies

Overview
Ethernet has been the most successful LAN technology mainly because of how easy it is to implement. Ethernet has also been successful because it is a flexible technology that has evolved as needs and media capabilities have changed. This module will provide details about the most important types of Ethernet. The goal is to help students understand 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. A faster Ethernet version called 10-Gigabit Ethernet is now widely available and faster versions will be developed.

MAC addresses, 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 NICs capable of 10, 100, or 1000 Mbps 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 cables in most new installations.

This module covers some of the objectives for the CCNA 640-801, INTRO 640-821, and ICND 640-811 exams.

Students who complete this module should be able to perform the following tasks:

• Describe the differences and similarities among 10BASE5, 10BASE2, and 10BASE-T Ethernet
• Define Manchester encoding
• List the factors that affect 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