What is TCP/IP Model | 5 layers Explained

What is TCP/IP?

• TCP/IP (Transmission Control Protocol/Internet Protocol), is a set of communication protocols that form most computer networks.
• It consists of five layers, each with specific functions and responsibilities.

Layers of TCP/IP Model

• Application Layer
• Transport Layer (TCP/UDP)
• Network/Internet Layer (IP)
• Data Link Layer (MAC)
• Physical Layer

Application Layer

• The Application Layer is the topmost layer and is responsible for end-user applications and services.
• It directly interacts with software applications and provides a platform-independent interface.

Protocols

• HTTP (Hypertext Transfer Protocol): HTTP operates in this layer, facilitating communication between web browsers and web servers.
• SMTP (Simple Mail Transfer Protocol): SMTP is used for sending emails.

Transport Layer

• The Transport Layer is responsible for end-to-end communication between devices on different hosts.
• It ensures data delivery, error detection, and reliability.

Protocols

• TCP (Transmission Control Protocol): TCP provides reliable, connection-oriented communication.
• For example, when you download a file from a web server, TCP ensures that all the data arrives without errors, retransmitting any lost packets.
• UDP (User Datagram Protocol): UDP offers a lightweight, connectionless communication method.
• It's used for applications where speed is more critical than reliability, such as video streaming or online gaming.

Physical Layer

• The Network Access Layer, also referred to as the Physical Layer is responsible for the physical transmission of data over the network medium.
• It deals with hardware-specific details like electrical signals, cables, and network interfaces.

Protocols

• Ethernet: This layer governs the way data is placed onto the physical medium, typically using Ethernet frames.
• For example, when you connect to the internet via Wi-Fi, your device interacts with your router's Ethernet ports.
• MAC Addresses: The Media Access Control (MAC) address is a hardware address assigned to each network interface card (NIC) to uniquely identify devices on a local network.

Internet Layer/Network Layer

• The Internet Layer, often referred to as the Network Layer, is responsible for routing packets of data between different networks.
• It ensures data reaches its destination regardless of the underlying physical networks.

Protocols

• IP Addressing: Internet Protocol (IP) addresses are assigned to devices on the internet to identify them uniquely.
• Routing: Routers operate at this layer to determine the best path for data to travel across networks.

Conclusion