🌐 Introduction to the Transport Layer The Transport Layer in the OSI model is responsible for end-to-end communication between devices. It ensures that data is transferred reliably and efficiently across the network, providing services such as:
Connection-oriented communication (TCP) Connectionless communication (UDP) 🏷 Transport-Layer Services Key services provided by the transport layer:
Port Addressing: Identifies different processes running on the same device using port numbers (e.g., port 80 for HTTP). Socket Addressing: Combination of an IP address and a port number to uniquely identify a connection. Flow Control: Manages the rate of data transmission to prevent congestion. Error Detection and Recovery: Ensures data integrity through checksums and retransmission (in TCP). Multiplexing: Enables multiple applications to use the network concurrently through different ports. 🔗 Port and Socket Addresses Port Address: A 16-bit number (0-65535) used to identify the sending/receiving process on a device. Ports 0-1023 are reserved for well-known services. Socket Address: A combination of an IP address and a port number (e.g., 192.168.1.1:80). 🚀 Real-world Example HTTP Request (TCP): A client communicates with a web server on port 80 to request a page, and the transport layer ensures that the data reaches the right application by utilizing the correct socket address. 🧠 Insights The transport layer is critical for managing communication between networked applications, ensuring reliability (TCP) or low overhead (UDP) depending on application needs. 🔗 Links Next: UDP: Introduction and Remote Procedure Call (RPC)