Design & Implementation Of File Transfer Function In CMT

This paper studies the design and the implementation of File Transfer Module in OAM subsystem of CMT system. File Transfer Module is an important part of OAM. It is used to transmit information such as programs, data files, bills or statistics between OAM Server and Client. The implementation of File Transfer Module is based on FTP. Although FTP is a sophisticated protocol, there are also some problems to be solved in application to CMT system which should be high reliability, platform independent, etc.The main work of this paper is as follows:Some protocols are researched which are correlative to File Transfer. These protocols involve FTP, HTTP, FTAM and so on. It puts emphasis on FTP. It analyses the FTP Client/Sever Model and the implementation of File Transfer based on FTP.According to the requirements of File Transfer in CMT, this paper proposes the design of FTP client. FTP client provides multifarious File Transfer Services needed, and it is user-friendly, multi-platform and flexible to many different OSs (Vxworks, Windows, Unix, etc.). The application of FTP client is realized with the Java programming language.The FTP server task provided along with Vxworks OS is analyzed. The result indicates that some characteristics of the server can't meet the requirements of File Transfer in CMT. Therefore, a FTP server is redesigned. Compared with FTP server task provided along with Vxworks OS, it expands some FTP commands and improves the reliability.This paper studies resuming downloading and multithreading downloading with resuming capability in FTP client, and discusses the key point of the implementation with Java language. These functions have significance on File Transfer.This paper studies the FTP Security Extensions Protocol and some counter measures to FTP security. It also analyzes some problems in FTP data connection with Passive mode and Port mode.At last, it summarized the whole work and gives the advanced study direction.