The Design And Implementation Of Reliable File Transfer Protocol Over Unidirectional Broadcast Network

With the popularity of cable TV network, how to use unidirectional broadcast network more effectively is attracting more and more concerns. In unidirectional broadcast network, applications have become increasingly diversified, such as distance education, such as the decentralization policy document. In these applications, file transfer is essential. How to achieve reliable file transfer system in such networks is an important application area.In this paper, we take a deep analysis and research on application and technology of reliable multicast file delivery transfer system, On top of the ALC protocol, we presents a reliable multicast file transfer protocol by combining FEC, CRC32 and MD5 algorithms. We achieve a highly efficient and reliable sending and receiving system. This work is innovative and also has considerable reliability, it provides a reference for file transferring over unidirectional broadcast network.The paper also tries to improve the performance, in order to improve the receiving performance and reduce the requirements of the client, we do some detailed experiments, and then do some curve fitting and mathematical analysis to test the crucial working parameter (file fragment size), and finally we get the best experience-based parameter expression. This work does some exploring on tuning the performance based on real applications, which has some practicability.In this paper we also design and implement resume-transfer in client program in order to reduce disk occupation and improve receiving performance, which also reduce the requirements of clients' hardware. To resume transferring over unidirectional broadcast network is also innovative.The protocol has been already implemented and successfully applied in practice. PC users can experience reliable file downloading at high speed with QoS assurance by access to the CATV network using DVB Network Interface.