Basics of Port Addressing

Port = Communication end point

• In computer networking, a port address is a 16 bit numeric identifier used to specify a unique communication end point within a device.

• Ports are essential for data traffic.

• They enable multiple applications or services on a single device to use the network simultaneously without interference.

• Port numbers fall into three main ranges: Well-Known Ports (0–1023) for core services like HTTP (80) and HTTPS (443), Registered Ports (1024–49151) for user-installed applications like MySQL (3306), and Dynamic/Private Ports (49152–65535) for temporary connections.

• In the TCP/IP model, a port number combines with an IP address to form a socket, which directs traffic to the correct process or service.

• In a node, many processes will be running.The data sent/received must reach the right process.

• Fixed port numbers and dynamic port address(0 - 65535).

• Example: Fixed port number -25,99 etc.

OS assigned dynamic port numbers :62414.

→Reaching our city = Reaching our network(IP address).

→Reaching our Apartment = Reaching the host(MAC address).

→Reaching the right person = Reaching the right process(Port number).

• Overall, port addresses are essential for managing data flow, allowing for efficient and organized communication between applications and services across a network.

Each application or service (e.g., Internet Explorer, Firefox, Media Player) is assigned a unique port number for data exchange, allowing multiple applications to run simultaneously without conflicts.