TCP/IP Model

Function: Provides end-to-end communication services, ensuring data is transferred reliably or quickly between hosts, equivalent to the OSI model’s Transport layer.

Key Responsibilities:

Segments and reassembles data for transmission.

Manages flow control to prevent overwhelming the receiver.

Ensures reliable delivery (e.g., retransmission for lost packets) or fast delivery (no retransmission).

Uses port numbers to identify applications or services.

Supports connection-oriented (TCP) or connectionless (UDP) communication.

Examples:

Protocols: Transmission Control Protocol (TCP), User Datagram Protocol (UDP).

Port Numbers: 80 (HTTP), 443 (HTTPS), 53 (DNS).

Technologies: TCP three-way handshake (for reliable connections), UDP for streaming or gaming.

Analogy: The Transport layer is like a courier service, either guaranteeing delivery with tracking (TCP) or sending packages quickly without confirmation (UDP).