总结：

• TCP：可靠、有序、面向连接，但由于开销和连接管理而速度较慢。
  • **适用于：**数据完整性和顺序至关重要的应用程序（例如，网页浏览、电子邮件）。
• **UDP：快速、无序、无连接，**速度快但不可靠，适合实时应用。
  • **适用于：**速度比可靠性更重要的应用（例如，直播、在线游戏）。

Overview of Internet Protocol Suite (TCP/IP)

• TCP/IP Suite: Commonly referred to as TCP/IP, which stands for Transmission Control Protocol over Internet Protocol.
• Misconception: It is often mistakenly believed that the suite only includes TCP and IP, but it also encompasses other protocols like UDP (User Datagram Protocol).

TCP (Transmission Control Protocol)

Reliability and Ordering

• Data segmentation: Large data sets are segmented into smaller packets for transmission.
• Reassembly: Reassembles data packets in the correct order at the destination.
• Error checking and retransmission: Missing packets are resent to ensure data integrity.

How to guarantee the reliabilty?

• Connection Establishment: Establishes a two-way connection for reliable communication.

  

  • To establish this two way connection, we use Three-Way Handshake, which is a component of TCP:
    • improve reliability but expensive(takes more time and money)
    • three steps:

      • SYN: Client sends a synchronize message to the server.

      • SYN-ACK: Server responds with a synchronize and acknowledge message.

      • ACK: Client sends an acknowledgement back to the server.

        

Benefits of TCP

• Reliable Data Transfer: Guarantees complete data transfer without loss.
• Order Maintenance: Data arrives in the order it was sent.
• Applications:
  • HTTP (HyperText Transfer Protocol): Web browsing.
  • SMTP (Simple Mail Transfer Protocol): Email transmission.
  • WebSockets: Full-duplex communication channels over a single TCP connection.
  • Many more protocols rely on TCP for reliable communication.

Drawbacks of TCP

• Overhead: Additional data for establishing and maintaining the two way connections.