Concept Exercise Chapter 7 Name:
Date: Class:

Cisco Exercises - Semester 1 - Networking Fundamentals
Chapter 7 Layer 2: Technologies


Introduction

Ethernet was developed by Xerox Corporation's Palo Alto Research Center (PARC)
in the 1970s. Ethernet is the most popular LAN standard today. There are
millions of devices or nodes on Ethernet LANs. The early LANs required very
little bandwidth to perform the simple network tasks required at that
time-sending/receiving e-mail, transferring data files, and handling print
jobs. In 1980, the Institute of Electrical and Electronic Engineers (IEEE)
released the IEEE 802.3 specification for which Ethernet was the technological
basis. Shortly thereafter, Digital Equipment Corporation, Intel Corporation,
and Xerox Corporation jointly developed and released an Ethernet specification
(Version 2.0) that is substantially compatible with IEEE 802.3. Together,
Ethernet and IEEE 802.3 currently maintain the greatest market share of any LAN
standard. An Ethernet LAN is used to transport data between network devices,
such as computers, printers, and file servers. Ethernet is known as a
shared-medium technology; that is, all the devices are connected to the same
delivery media. Delivery media refers to the method of transmitting and
receiving data. For example, a handwritten letter can be sent (transmitted)
using one of many delivery methods, such as the U.S. postal service, Federal
Express, or fax. Electronic data can be transmitted via copper cable, thick
coaxial cable, thinnet, wireless data transfer, and so on.

Concept Questions

Demonstrate your knowledge of these concepts by answering the following
questions in the space provided.

Ethernet, Fiber Distributed Data Interface (FDDI), and Token Ring are widely
used LAN technologies that account for virtually all deployed LANs. LAN
standards specify cabling and signaling at the physical and data link layers of
the OSI reference model. Because they are widely adhered to, this book covers
the Ethernet and IEEE 802.3 LAN standards. Why do you suppose that Ethernet
technology is so heavily used?

When it was developed, Ethernet was designed to fill the middle ground between
long-distance, low-speed networks and specialized, computer-room networks
carrying data at high speeds for very limited distances. Ethernet is
well-suited to applications in which a local communication medium must carry
sporadic, occasionally heavy traffic at high-peak data rates. Why is Ethernet
so well suited to this kind of traffic?

Today, the term standard Ethernet is used refer to all networks using Ethernet
(a shared-medium technology) that generally conform to Ethernet specifications,
including IEEE 802.3. In order to use this shared-medium technology, Ethernet
uses the carrier sense multiple access collision detection (CSMA/CD) protocol
to allow the networking devices to negotiate for the right to transmit. What
are the major benefits of Ethernet?