IMPLEMENTATION OF FILE TRANSFER PROTOCOL IN CLIENT SERVER MODEL

Abstract

The FTP is basic and common service to exchange files between computers, namely hosts, over TCP/IP networks e.g., private networks or Internet. The FTP supports file transmission and character code conversion when exchanging text or binary files. The use of FTP is effective in exchanging or distributing of large volume of data over private networks and/or the Internet. FTP uses TCP as a transport protocol to provide reliable end-to-end connections. As it is necessary to log into the remote host, the user must have a user name and a password to access files and directories. The user who initiates the connection assumes the client function, while the server function is provided by the remote host. The thesis starts with an introduction to the basic networking and the OSI model, giving background to to grasp the rest of the contents. Then next is the explanantion of the Client Server Model.Follwing this is a report on File Transfer Protocol. It explains the various functions that the File Transfer Protocol performs. FTP can be used to download the files from a server node to the client node or upload a file from a client node to the server node. FTP can also be used to change the current working directory of the server/client and also can delete files on the server station. After this there are details of socket programming. Socket programming has been used extentensively throughtout the project. The various functions that have been frequently used like socket ( ), bind ( ), accept ( ), send ( ) etc have been explained along with all the possible forms that these functions can take. Next is the implementation of such a File Transfer Protocol using the programming language C. The functions being implemented in the the code are open, quit, exit, username, password, download, upload, change directory, show present working directory, list the contents of the current working directory. The code can be run on a Linux platform. In the next section, File Transfer Protocol is implemented using JAVA. The functions being implemented are Connect, Disconnect, Download, Upload and Delete. This code is platform independent and thus can be run on a variety of platforms like Windows and Linux. This gives its users an added advantage of platform independence. 6 The C and Java implementations are followed by their respective possible outputs and errors. Also a brief comparison between the the codes is also done highlighting the major advantages and disadvantages of using C and JAVA.