The Design And Implementation Of End-to-end Reliable Transmission System Based On IP Multicast

IP Multicast is a bandwidth-conserving technology specifically designed to reduce traffic by simultaneously delivering a single stream of information to potentially thousands of corporate recipients or homes. By replacing copies for all recipients with the delivery of a single stream of information, IP Multicast is able to minimize the burden on both sending and receiving hosts and reduce overall network traffic. So it becomes more and more widely used in many fields. In the case of a high-bandwidth application, such as video conferencing, video on demand, network television and so on, IP Multicast can benefit situations with only a few receivers because a few video streams would otherwise consume a large portion of the available network bandwidth. Moreover, IP Multicast inherent has the transmission mode of "does everything possible". Therefore, the IP Multicast application is unable to guarantee the reliability of the data packet transmission and reception sequence. Thus the reliability of IP Multicast is an urgent problem to solute. This thesis mainly is to the characteristic of large-capacity file transfer, and the reliability of the end-to-end transmission based on IP Multicast gets to be further researched.This thesis first presents a brief introduction to the basic concepts of the IP Multicast, the IP Multicast architecture, the IP Multicast address, the IP Multicast protocol and the essential conditions for building IP Multicast applications which lay the solid theoretical foundation for the further study of the end-to-end reliable transmission based on IP Multicast.Second, the existing error recovery mechanism is in-depth study such as the automatic repeat request techniques and the forward error correction technology. According to the large-capacity files transfer which have characteristics of lasted for a long time, occupation of a high-bandwidth as well as ensuring the lost data available to restore in limited time, one type of end-to-end error recovery mechanism is proposed. It is the mix of automatic repeat request techniques based on end-to-end NACK, SACK and forward error correction technology based on digital fountain. And its principles are expatiated in detailed. At the same time, according to the present situation of network congestion and IP Multicast, the extension of the congestion control mechanism, the evaluation criteria, the scalability and TCP-Friendly fairness characteristics are studied, the predecessor's congestion control mechanisms are analyzed, and improved end-to-end congestion control mechanism of IP Multicast based on the sent rates is proposed.Third, the Windows socket network programming technology is comprehensively understood, and then combining the module design theory of the software engineering, the module overall arrangement has been carried on to this system. High encapsulation is taken to main module, which has a good reusability and scalability properties. At the same time, the communication technology of multithread and overlapped I/O model are adopted on the control of the server-side subsystem and client-side subsystem, which have increased the utilization ratio of CPU greatly, and improved response time and reacting efficiency of the system.Finally, the functions and performance of this system have been comprehensive tested. Just as the data showed in the test, this system can work well to achieve the files completely received among the end systems when transmitting many kinds of large-capacity files.