The difference between tcp and udp

The difference between tcp and udp: 1. Connectivity, TCP is a connection-oriented protocol, and UDP is a connectionless protocol; 2. Reliability, TCP has very strict requirements on the reliability of data. UDP has lower requirements for data reliability; 3. Speed ​​and efficiency, TCP requires the establishment of a connection and the use of acknowledgment retransmission mechanism, UDP is not restricted by congestion control; 4. Data packet size, TCP divides the data into smaller data Packets are transmitted, and UDP allows multiple data packets to be packaged into a larger datagram for transmission; 5. Applicable scenarios, etc.

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are two transport layer protocols commonly used in computer networks. Although they are both used to send data over a network, they have important differences in how they work and what they do. This article will introduce the differences between TCP and UDP in detail.

1. Connectivity:

TCP is a connection-oriented protocol, which requires a connection to be established before data transmission. This means that the sender and receiver must first perform a three-way handshake and establish a connection before they can start transmitting data. UDP is a connectionless protocol. The sender does not need to establish a connection with the receiver in advance and can directly send data to the receiver.

2. Reliability:

TCP has very strict requirements on data reliability. It uses acknowledgment and retransmission mechanisms during transmission to ensure data integrity and correctness. If the receiver does not receive the data, the sender will continue to retransmit it until the receiver confirms receipt of the data. UDP has lower requirements for data reliability and does not provide confirmation, retransmission and flow control mechanisms. If the data sent by the sender is lost or damaged, UDP will not retransmit it, but will directly cause the data received by the receiver to be incomplete.

3. Speed ​​and efficiency:

Because TCP requires establishing a connection and using a confirmation retransmission mechanism, it is usually slower than UDP. UDP does not have the overhead of connection establishment and confirmation retransmission, so it is usually faster than TCP in terms of data transfer speed. In addition, due to TCP's congestion control mechanism, when the network is congested, TCP will reduce the sending rate, causing the transmission speed to further decrease, while UDP is not restricted by congestion control.

4. Packet size:

TCP divides data into smaller packets for transmission and adjusts them according to network conditions. It has no fixed datagram size limit. UDP allows the sender to package multiple data packets into a larger datagram for transmission at one time. The size of the datagram is generally determined at the application layer.

5. Applicable scenarios:

TCP is suitable for application scenarios that require high data reliability, such as file transfer, email and web browsing. UDP is suitable for application scenarios that require high real-time data performance, such as audio and video streaming, online games, and real-time communications.

To sum up, there are significant differences between TCP and UDP in terms of connectivity, reliability, speed and efficiency, datagram size, and applicable scenarios. Understand their differences, and you can choose the appropriate protocol for data transmission based on actual needs to ensure safe, stable and efficient data transmission.

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