Prolog to internet multicast routing and transport control protocols

The defining mission of the Internet is to deliver data efficiently to a network of diverse groups and individuals. To do this, the Internet must be able to multicast data to large numbers of selected receivers, simultaneously and with a minimum rate of error. In addition, the protocols for achieving this must be scalable, i.e., they must be capable of operating efficiently even as the size of the network increases. However, multicast techniques now in use are far from mature. This paper focuses on three major areas of multicast technology that the authors feel need further research and development: 1) scalable multicast routing; 2) reliable multicast; and 3) multicast flow and congestion control. The authors review various schemes and protocols for resolving these issues and also discuss the reasoning and design philosophy behind them. Their goal is not only to summarize existing work, but also to stimulate further research in these important areas. The Internet is actually a loose construct of networks, provided by primary network service providers (NSPs) Internet Multicast Routing and Transport Control Protocols as MCI WorldCom, Sprint, AT&T WorldNet, and Internet II. These networks are interconnected by high-speed links that allow service providers entry into the Internet through network access points. These three elements—namely, networks of NSPs, high-speed links interconnecting them, and access points—constitute the backbone of the Internet. Service providers are each allocated blocks of addresses on the network, which they further apportion to their customers. Multicasting is the process of sending messages or datagrams simultaneously to a mix of different addresses on the network. Multicasting, however, is a selective process. Unlike broadcasting, which transmits indiscriminately to all receivers on a network, multicasting transmits only to those addressees for whom the message is relevant. It is, thus, essential both for accuracy and efficiency to ensure that only those designated addressees receive the intended message. This is accomplished by multicast routers, which read the address codes on the datagrams and direct them to the correct destinations. The Internet’s multicast architecture currently runs off three types of protocols: 1) group management protocols, which supply the data on group members needed by the routers; 2) routing