f the POP has become incredibly more sophisticated today than it was in the beginning; the architecture has evolved in response to and in preparation for a very wide range of multimedia, real-time, and interactive applications. Internet Challenges and Changes Despite all its advances over the past couple decades, the Internet is challenged today. It is still limited in bandwidth at various points. The Internet is composed of some 10,000 service providers. Although some of the really big companies have backbone capacities that are 50Gbps or greater, there are still plenty of small back- bones worldwide that have only a maximum of 1.5Mbps or 2Mbps. Overall, the Internet still needs more bandwidth. One reason the Internet needs more bandwidth is that traffic keeps increasing at an astonishing rate. People are drawn to Web sites that provide pictures of prod- ucts in order to engage in demonstrations and to conduct multimedia communica- tions, not to mention all the entertainment content. Multimedia, visual, and interactive applications demand greater bandwidth and more control over latencies and losses. This means that we frequently have bottlenecks at the ISP level, at the backbone level (i.e., the NSP level), and at the Internet exchange points (IXPs) where backbones interconnect to exchange traffic between providers. These bottle- necks greatly affect our ability to roll out new time-sensitive, loss-sensitive applica- tions, such as Internet telephony, VoIP, VPNs, streaming media, and IPTV. And remember, as discussed in the Introduction, one other reason more bandwidth is needed is that in the future, everything imaginable-your TV, refrigerator, electri- cal outlets, appliances, furniture, and SO on-will have IP addresses, thus vastly increasing demand. Chapter 8 The Internet and IP Infrastructures Therefore, we are redefining the Internet, with the goal of supporting more real- time traffic flows, real audio, real video, and live media. This requires the introduc- tion of QoS into the Internet or any other IP in