TCP

TCP (Transmission Control Protocol) is one of the core protocols of the internet, defining how to reliably transmit data across networks. TCP is a transport layer protocol, positioned between the application layer and network layer, primarily used to provide reliable, connection-oriented communication services.

Features of TCP

• Reliability: TCP provides reliable data transmission services, ensuring packets arrive at the receiver in order and without errors.
• Connection-Oriented: TCP requires establishing a connection before communication begins (three-way handshake) and disconnecting after communication ends (four-way handshake).
• Flow Control: Uses sliding window protocol to prevent the sender from transmitting data too quickly.
• Congestion Control: Detects network congestion and reduces data transmission rate, including algorithms such as slow start and congestion avoidance.
• Ordered Transmission: Ensures packets arrive at the receiver in the order they were sent.

Application Scenarios

• Web Browsing: HTTP/HTTPS protocols are based on TCP.
• Email: SMTP, IMAP, and POP3 protocols are based on TCP.
• File Transfer: FTP protocol is based on TCP.
• Remote Login: SSH and Telnet protocols are based on TCP.