of its network management, restoration, and reliability capabilities. Table 7.1 IP Versus ATM Services Transport Benefit Drawback Supported Packet Size Header Pervasive at No QoS Data, voice Variable, 40 bytes the desktop 40-64,000 bytes Multiple Small cell size Data, voice, Fixed cells, 5 bytes service that is ineffi- IP, Frame 53 bytes classes cient for data Relay, X.25, transport leased lines Packet-Switched Networks The MFA Forum The MFA Forum (www.mfaforum.org) is an international, industrywide, nonprofit associ- ation focused on advancing the deployment of multivendor, multiservice packet-based networks, associated applications, and interworking solutions. The MFA Forum Web site is the best resource for finding information on existing and planned standards and speci- fications for the three main contemporary packet-switched networks: Frame Relay, ATM, and MPLS. (MPLS is discussed in Chapter 10.) This page intentionally left blank Chapter The Internet and IP Infrastructures This chapter explores the Internet, including how today's Internet actually works, the protocols-such as Internet Protocol (IP)-that make the Internet what it is, how addressing works on the Internet, the organization and characteristics of the variety of service providers, and how IP QoS can be used to ensure maximum net- work performance. It also takes a glimpse at some of the exciting developments that spell the future of the Internet. Internet Basics Figure 8.1 is an astounding graph that speaks to the pace of Internet development. It shows the number of years it took several technologies to reach 50 million users worldwide. As you can see, whereas it took 74 years for the telephone to reach 50 million users, it took the World Wide Web only 4. A number of forces are propelling our interest in the Internet. One main force is that usage continues to grow at an impressive rate. Today, more than 1 billion people actively use the Internet, although there are vast differences in the penetra- tion and usage rates around the world. Recent sta