is Gigabit Ethernet, particu- larly when deployed in a switched configuration, offering speeds in excess of 1 Gbps. Finally, optical networking is carving out a large niche Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Transport Technologies Transport Technologies for itself as a bandwidth-rich solution with the potential for inherent quality of service (QoS). We begin our discussion with dedicated private line technologies, oth- erwise known as point-to-point technologies. Point-to-Point Technologies Point-to-point technologies do exactly what their name implies: They connect one point directly with another. For example, it is common for two buildings in a downtown area to be connected by a point-to-point microwave or infrared circuit, because the cost of establishing it is far lower than the cost of putting in physical facilities in a crowded city. Many businesses rely on dedicated, point-to-point optical facilities to interconnect locations, especially businesses that require dedicated bandwidth for high-speed applications. Of course, point-to-point does not necessarily imply high bandwidth; many locations use 1.544 Mbps T1 or 2.048 Mbps E1 facilities for interconnection, and some rely on lower- speed circuits where higher bandwidth is not required. Dedicated facilities provide bandwidth from as low as 2,400 bits per second to as high as multiple gigabits per second. Analog facilities run- ning at 2,400 bps are not commonly seen but are often used for alarm cir- cuits and telemetry, while circuits operating at 4,800 and 9,600 bps are still used to access interactive, host-based data applications. Higher-speed facilities are usually digital and are often channelized by dedicated multiplexers and shared among a collection of users or by a variety of applications. For example, a high-bandwidth facility that inter- connects two corporate loc