Networking Explained, 2nd Edition

Chapter 8: Ethernet, Ethernet, and More Ethernet 313

mine traffic loads and patterns, user applications, location of users and servers, and type of

data transmissions. In some cases, giving attention to specific network administration

tasks might prove sufficient. For example, Ethernet/802.3 performance and efficiency can

be improved through collision management, standards adherence, proper system configu-

rations, software upgrades, and segmentation using bridges. Nevertheless, there are certain

situations that lend themselves to switching. These include dynamic workgroup settings,

frequent data transmissions involving large data files such as graphical images, distributed

network environments that employ several servers, and LANs that must support video or

multimedia applications. If a decision to “switch” is made, remember that all switches are

not alike. Switches have different architectures, are designed for different types of applica-

tions, and some switches also have routing capabilities (called layer-3 switches). Once

again it is important to understand how a network is being used before modifying it.

41. What’s next?

100-Mbps Ethernet, 1000-Mbps Ethernet, and 10,000-Mbps Ethernet.

42. Why are these needed when switched and full-duplex Ethernet are available?

Although switched and full-duplex Ethernet—and segmentation—improve overall net-

work performance, these implementation strategies for enhancing 10-Mbps Ethernet per-

formance do not actually increase data transmission rates, that is, they do not speed up the

network. To address this issue of speeding up the network, IEEE increased Ethernet/802.3’s

10-Mbps data transmission rate, first to 100 Mbps, then to 1000 Mbps, and in the very near

future, to 10,000-Mbps Ethernet. This strategy of speeding up the network is different from

the 10-Mbps Ethernet strategies discussed earlier and can be best understood by viewing

a network as a crowded highway. A strategy that employs segmentation, switched Ethernet,

or full-duplex Ethernet adds more lanes to the highway. A 100-Mbps, 1000-Mbps, or

10,000-Mbps technology, however, actually increases the speed limit of the highway by

orders of magnitude, from 10 Mbps to 100 Mbps to 1000 Mbps to 10,000 Mbps.

43. Why do we need to increase the speed of the LAN?

There are several reasons. First, the introduction of more sophisticated operating sys-

tems and applications, faster processors, and greater disk and memory capacities, has led

to a pronounced degradation in overall network and application performance. Second,

many companies now use Internet technologies to build private, corporate intranets that

rely on standard web browsers such as Netscape’s Communicator and Microsoft’s Internet

Explorer to provide employees with access to critical corporate data. These web browsers

are capable of supporting bandwidth-intensive rich media data types, including high-reso-

lution graphics, 3D imaging, audio, video, and voice. Third, the introduction of multime-

dia client/server applications, the deployment of network computers and Java-based

servers, and an increasing number of network users, are taxing first-generation Ethernet.

44. What’s the history of 100-Mbps Ethernet?

The concept of 100 Mbps Ethernet was first introduced in 1992. By August 1993, the

Fast Ethernet Alliance (FEA) was formed. Within two years, membership grew to more