Introduction
Understanding how the internet works might seem hard because of the complicated network rules. But, at its heart, the internet uses a set of guidelines for sharing data that makes sure communication between devices is fast and dependable.
What is a Protocol?
A protocol is a set of rules that dictate how two entities on a network communicate. It's like the behavior of sharing and getting data on the internet.
IP: The Internet Protocol
IP (Internet Protocol) is the foundational protocol that defines the method for sending data across the internet. It operates by exchanging packets of information between devices, each identified by a unique IP address. There are two main versions of IP in use today:
IPv4: The original IP addressing system, which uses 32-bit addresses. Due to the internet's growth, IPv4 addresses are in short supply.
IPv6: The newer version that uses 128-bit addresses, significantly increasing the number of available addresses.
An IP packet consists of two parts: a header (containing metadata like source and destination IP addresses) and the data payload.
The header is 20 to 60 bytes long, while the maximum size for the data payload is 65,536 bytes, also calculated as 2^16. This size limitation means large files must be divided into multiple packets for transmission.
TCP: Ensuring Reliable Delivery
While IP handles data packet routing, TCP (Transmission Control Protocol) ensures the reliable delivery of data across the internet. TCP addresses the limitation of IP packets' size by enabling the transmission of large data sets and ensuring packets arrive in the correct order. It adds a layer of control by including its own header in the data part of the IP packet, with information like source and destination ports and sequence numbers.
TCP establishes a connection through a three-way handshake:
The client sends a SYN (synchronize) packet to the server to request a connection.
The server responds with a SYN-ACK (synchronize-acknowledge) packet, agreeing to the connection.
The client sends an ACK (acknowledge) packet back, and the connection is established.
This handshake ensures that both the client and server are ready for data exchange.
HTTP: Structuring the Data
TCP provides a robust method for data transmission, but it doesn't define how data should be structured. This is where HTTP (HyperText Transfer Protocol) comes in.
HTTP is a protocol that outlines how clients (like web browsers) and servers should communicate, specifying the format for requests and responses.
An HTTP request includes information like the host (e.g., www.youtube.com), port (typically 80 for HTTP), method (e.g., GET), path (e.g., /watch?v=123), and optionally headers and a body.
An HTTP response from the server contains a status code (e.g., 200 for success), headers, and a body containing the requested data.
Conclusion
IP, TCP, and HTTP work together to make internet communication possible. They help devices connect, talk, and share data easily and dependably. IP sends data packets, TCP makes sure they arrive correctly and in order, and HTTP organizes the data exchange. Knowing these protocols helps us understand how the internet works and makes it seem less complicated.
