From Packets to Protocols: How Networks Communicate

"Have you ever wondered how the Internet works or how it communicates with servers and other devices?"

In network communication, understanding the transition from packets to protocols is crucial. Data is systematically divided into packets, enabling efficient transmission across various channels.

Protocols are crucial in ensuring that these packets arrive at their destination accurately and in the correct order. Mastering these concepts is essential for a comprehensive understanding of how networks operate and communicate effectively.

Networks rely on various protocols, including TCP, UDP, and HTTP.

This article discusses various networking protocols that enable communication between all networks.

TCP → Transmission Control Protocol

TCP (Transmission Control Protocol) is purely Reliable, Ordered, and based on a 3-way Hand-shake mechanism.

• Reliable → It means that there is no loss in data packets between transmissions.

• Ordered → If the client syncs any request to the server, it acknowledges the request in the same order.

  3-way Handshake -

• SYNC (Synchronize) - The client starts the connection by sending data packets to the server. There is no loss in data packets when sending SYNC to the server.

• SYNC + ACK (Synchronize - Acknowledge) - The server responds with a SYNC and an ACK response to the client.

• Acknowledge - The client sends an ACK packet back to the server for its SYNC request.

UDP → User Datagram Protocol

UDP (User Datagram Protocol) is a lightweight, connectionless transport layer protocol used for fast, low-latency data transmission. UDP is unreliable, taking more time and having no ordering guaranteed protocol.

Let's understand how UDP communicates with the server.

• Step 1 → The client sends a UDP data packet to the server or the receiver's end. The packet travels through the network without establishing a connection.

• Step 2 → The server may receive the data packet in the wrong order, or it might be lost.

• Step 3 → The receiver does not send an ACK back.

Since there is no connection management, UDP is much faster but less reliable than TCP.

HTTP → Hypertext Transfer Protocol

Hypertext Transfer Protocol is a set of rules used to transfer Hypertext (Web Documents) in a human-readable format. It is a request-response protocol that enables communication between a client and a server.

The HTTP process consists of the following steps -

• Client Request - The client sends an HTTP request to the server. The request includes several methods like GET, POST, PUT, DELETE, etc.

• The server responds to the Request - The server receives the request and processes it.

• Server sends a Response - The server sends back an HTTP response to the client. The response contains information like the Status Code for each request. The common Status Codes are 200 OK, 404 Not Found, and 500 Internal Error.

• Client processes the Response - The client receives and processes the response. If it's an HTML page or an app, the browser renders it; otherwise, it displays the Status Code.

Different versions of HTTP -

The first version of HTTP is known as HTTP 1, and the next version is HTTP 1.1, which serves as a fallback but is still in use. The most common version now is HTTP 2. HTTP 2 uses compression, reduces header size, employs encryption (often used with HTTPS), and allows for faster data transmission.

Networking protocols are crucial for modern communication, with TCP ensuring reliable and ordered data delivery, UDP offering low latency for real-time applications, and HTTP facilitating secure and efficient communication between web clients and servers.