rotocols are being developed to address real-time traffic, CoS, QoS, and security. Distributed network intelligence is being used to share the network functionality. At the same time, broadband access line deployment continues around the world, with new high-speed fiber alternatives, such as passive optical networks (PONs), gaining interest. (PONs are discussed in Chapter 12.) An impres- sive number of wireless broadband alternatives are also becoming available, as dis- cussed in Chapter 15, "WMANs, WLANs, and WPANs." Service Providers and Interconnection There is a wide range of service providers in the Internet space, and they vary greatly. One way they differ is in their coverage areas. Some providers focus on sim- ply serving a local area, others are regionally based, and others offer national or global coverage. Service providers also vary in the access options they provide. Most ISPs offer plain old telephone service (POTS), and some offer ISDN, xDSL, Frame Relay, ATM, cable modem service, satellite, and wireless as well. Providers also differ in the services they support. Almost all providers support e-mail (but not necessarily at the higher-tier backbone level). Some also offer FTP hosting, Web hosting, name services, VPNs, VoIP, application hosting, e-commerce store- fronts, and streaming media. Providers could service a very wide variety of applica- tions, and as a result, there is differentiation on this basis as well. Two other important issues are customer service and the number of hops a provider must take in order to get to the main point of interconnection to the Internet. It is pretty easy to become an ISP in a developed economy: Pick up a router, lease a 56Kbps/64Kbps line, and you're in business. But this is why there are some 10,000 such providers, of varying sizes and qualities, worldwide. And it is why there is a service provider pecking order: Research backbones have the latest technology, Chapter 8 The Internet and IP Infrastructures top-tier providers focus on business-class services, and