UDP Networks

We learned a lot about different types of data transfer protocols in the Computer Communications & Networks course at the University of Edinburgh. This repository contains Java implementations of those discussed protocols. Each protocol implementation contains a sender side and a receiver side, which work together to transfer any type of general data file.

The four protocols are:

basic framework
stop-and-wait
go-back-n
selective repeat

The implementations for each of these protocols use data packets with a maximum payload of 1 kilobyte (1024 bytes), with 3-byte headers, with 2 bytes representing a 16-bit message containing the packet sequence number and and 1 byte representing an end-of-file flag.

Usage

In this sender-receiver implementation, the receiver is the listener. With that in mind, the receiver must always be run before the sender is run. This is especially important in the basic framework, since it uses unreliable data transfer. In the other implementations, the sender will just stall until it finds a listener to connect to.

First, clone this repository and compile all of the Java files.

git clone https://github.com/hughhan1/Networks.git
cd UDP-Networks-master
javac *.java

Basic Framework

java BasicReceiver <portnumber> <filename>
java BasicSender localhost <portnumber> <filename>

Stop-And-Wait

java StopAndWaitReceiver <portnumber> <filename>
java StopAndWaitSender localhost <portnumber> <filename> <retrytimeout>

Go-Back-N

java GoBackNReceiver <portnumber> <filename> <windowsize>
java GoBackNSender localhost <portnumber> <filename> <retrytimeout> <windowsize>

Selective Repeat

java SelectiveRepeatReceiver <portnumber> <filename> <windowsize>
java SelectiveRepeatSender localhost <portnumber> <filename> <retrytimeout> <windowsize>

Usage Notes

For each of the protocols, localhost is the hostname used for the Inet Address. However, this does not have to be the case, although it does make everything a lot simpler!

hughhan1 / UDP-Networks