simple-datagram

Datagram is the unit of data exchanged between a pair of internet modules (includes the internet header). This program is built for enhancing the understanding of datagram based on RFC 791.

This repository contains a simple example of how to create and send datagrams using the UDP protocol in Go. The project includes two parts: a UDP server and a UDP client that sends datagrams to the server.

Overview

A datagram is a unit of data exchanged between two devices over a network using a connectionless protocol such as UDP (User Datagram Protocol). Unlike TCP, which establishes a connection before data transfer, UDP simply sends data packets (datagrams) without requiring a connection. This makes UDP faster but less reliable, as there is no guarantee of packet delivery.

This project demonstrates how to:

Create a UDP server that listens for incoming datagrams.
Create a UDP clients that sends datagrams to the server.

Project Structure

server.go: The UDP server code that listens for incoming datagrams on a specified port.
client.go: The UDP client code that sends a datagram message to the server.

How It Works

The server listens on port 8080 for incoming datagrams.
The client sends a datagram message ("Hello, this is a datagram!") to the server.
The server receives and prints the message along with the sender's address.

Running Example

Prerequisites

Go installed on your machine.

Steps

Run The Server:
- Open a terminal and navigate to the directory containing the server.go file.
- Start the server using the following command:
```
go run server.go
```
- The server will start listening on localhost:8080 for incoming UDP datagrams.
Run The Client:
- Open another terminal and navigate to the directory containing the client.go file:
- Send a datagram message to the server using the following command:
```
go run client.go
```

Output:

In the terminal server, you will see output like this when it receives a datagram:

Listening on localhost:8080
Received Hello, this is a datagram from 127.0.0.1:xxxxx

The client will display:

Sent message: Hello, this is a datagram!

Code Explanation

Server Code (`server.go`)

The server is implemented using Go's net package:

net.ResolveUDPaddr: Resolves the address for UDP communication.
net.ListenUDP: Binds the UDP address and starts listening for incoming datagrams.
conn.ReadFromUDP: Reads the incoming datagram into a buffer.

Client Code (`client.go`)

The client sends a datagram using:

net.ResolveUDPaddr: Resolves the server's UDP address.
net.DialUDP: Creates a UDP connection to the server.
conn.Write: Sends a datagram message over the UDP connection.

Notes

UDP is a connectionless protocol, meaning there is no guarantee that the datagram will reach the destination. It's faster but less reliable compared to TCP.
This example uses localhost communication, but you can modify the IP and port to test on different machines over a network.

License

This project is open-source and licensed under the MIT License.

garagaradev/simple-datagram