CS4445: Programming Assignment 3

Chat Application

Submission Instruction: Name of your code files should follow the format: cs4445YourNameChatClient.py

cs4445YourNameChatServer.py

Please write all your group members name on the top of the assignment. Your assignment will not be graded if name is missing.

******************************************************************* Chat Room

Problem Statement: Design a Chat application which has following features:

o It should use connection orient reliable Transport layer protocol o Chat Application follows client and multithreaded server architecture o Chat Room: Chat Messages are sent from everybody to everybody. o Standard message header: Notice that use of standard header will make applications developed by different users to be compatible with each other. Note that messages in only below format will be exchanged between server and client. Your application header must follow following field structure in the order of appearance. Following is the header structure in tuple format (Header Field, Header Size, description)  UNameL, 2 Bytes, Length of username in bytes  MessageL, 4 bytes, Length of message  Username, n, Username  Message, n, Message o Client Side User given parameters: IP address, port number, Username Note: any one is able to connect to any server

o Clients can come and go, when a new client (user) arrives the server should broadcast a message to all the clients with a message that someone has logged in and broadcast a message if server realizes someone has left. Server periodically displays a list of users.

Misc. Information/Tips: Your application must have above functionalities. You can extend the set of functionalities. Some extension ideas: Client can process commands and send command to the server (hint: add message type field in the application header), server can send the information about a particle user (view profile option), display a list of logged on users, Private messaging, authentication, Registration etc…

Important reading: Multithreading in python.