Python Sockets
- 1. Client Sockets vs Server Sockets • Server Sockets – A server socket is created using the python function socket.socket() – A sever socket needs to be bound to the specific IP address and a port number – Once bound on an IP and Port the socket has to listen by making the call socket.listen() – Listening is distinct which is what makes a socket a Server Socket – Server sockets accepts connections by calling the socket.accept() method
- 2. Client Sockets vs Server Sockets • Server Sockets – Every return of accept() function gives the server program a socket and an IP address pair of the client. – This client socket created for every client connection can be either processed sequentially or in a multithread way. – This Python Example Client-Server program exchanges messages on IPv4 addresses: https://pythontic.com/modules/socket/client-server-example
- 3. Client Sockets vs Server Sockets • Client Sockets – Client Socket need not “explicitly” bind itself to the IP/Port. – However, the kernel will associate an ephemeral port with the client socket and associate it to the local IP on which the socket is created. – The client socket need not listen for incoming connections. – Since the client socket is not listening for incoming connections it need not accept any connections as well.
- 4. Client Sockets vs Server Sockets • Client Sockets – Clients need not make below Python function calls • socket.bind() • socket.listen() • socket.accept() – Clients do make the following Python function calls • socket.Connect(), Socket.connectTo() (only for TCP sockets) • socket.recv()