TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are two different transport layer protocols, and they have some important differences in data transmission methods, characteristics, and application scenarios
1. Connectivity:
TCP: Provides a connection-oriented service. Before the data transfer, a reliable connection is established and disconnected after the data transfer is complete.
UDP: No connection protocol. Each packet is independent, and there is no persistent connection between the sender and receiver.
2. Reliability:
TCP: Provides reliable data transmission. Serial numbering, acknowledgment, and retransmission mechanisms ensure that data is transmitted sequentially and completely to its destination.
UDP: No reliability guarantees. Packets can be lost or out of order, and the application layer needs to handle them on its own.
3. Flow control and congestion control
TCP: Supports traffic control and congestion control to prevent network congestion and data loss.
UDP: It does not provide flow control and congestion control, and packets can be lost due to network conditions.
4. Packet size:
TCP: There is no fixed packet size limit. The data is split into TCP segments, which are dynamically resized based on network conditions.
UDP: There is a maximum transmission unit (MTU) and packets above this size will be fragmented.
5. Communication overhead:
TCP: Due to the establishment and maintenance of connections, as well as the mechanism of reliability assurance, the communication overhead is high.
UDP: Due to the lack of connections and fewer mechanisms, the communication overhead is small, and it is suitable for applications with high real-time requirements.
6. Application scenarios:
TCP: Ideal for applications that require reliable data transfer, sequential transfers, such as file transfers, web page visits, and more.
UDP: It is suitable for applications that require high real-time performance and can tolerate a small amount of data loss, such as audio streaming, gaming, etc.
7. Head Overhead:
TCP: The header has a large overhead and contains fields such as the serial number, confirmation number, and window size.
UDP: The header has a small overhead and contains only the basic source port, destination port, length, and checksum fields.
Overall, the choice between TCP and UDP depends on the specific needs of the application. TCP is suitable for scenarios that require reliability and orderliness, while UDP is suitable for scenarios that require high real-time performance and can tolerate a small amount of data loss.