What are the differences between tcp and udp?

The difference between tcp and udp: 1. Reliability, TCP provides reliable data transmission, ensuring data integrity and orderliness, UDP is a connectionless protocol; 2. Speed, TCP is more complex than UDP , slightly lower in transmission efficiency; 3. Connectivity, TCP is a connection-oriented protocol, which transmits data by establishing a connection, UDP is a connectionless protocol, which can send data directly; 4. Data packet size, TCP When transmitting data, the data is divided into smaller data blocks. There is no limit on the packet size of UDP.

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are two commonly used transmission protocols in computer networks. They have different characteristics and uses in network communications. This article will introduce the difference between TCP and UDP.

1. Reliability:

TCP provides reliable data transmission and ensures data integrity and orderliness. It ensures reliable transmission of data through sequence numbers, confirmation mechanisms and retransmission mechanisms. If data is lost or an error occurs, TCP automatically retransmits the lost data.

UDP is a connectionless protocol and does not provide reliability guarantees. It does not confirm arrival after sending data, nor does it retransmit lost data. Therefore, UDP is more suitable for some application scenarios that have relatively low reliability requirements, such as audio and video transmission.

2. Speed:

Because TCP provides reliability guarantees, it requires additional control information to maintain connection status and data transmission control. This makes TCP more complex than UDP and slightly lower in transmission efficiency.

UDP has no overhead of connection establishment and disconnection and requires only very little control information, so the transmission speed is faster. UDP is suitable for some applications with high real-time requirements, such as online games and real-time video transmission.

3. Connectivity:

TCP is a connection-oriented protocol that transmits data by establishing a connection. Before data is sent and received, a connection must be established first, and data can be sent only after the connection is established. During the connection establishment process, a "three-way handshake" is required, that is, three interactions to confirm the connection. This connectivity enables TCP to ensure the reliability of data transmission.

UDP is a connectionless protocol that can send data directly without establishing a connection first. This makes UDP less expensive and more real-time in sending data. But the disadvantage is that the reliability of data transmission cannot be guaranteed.

4. Data packet size:

When TCP transmits data, it divides the data into smaller data blocks and adjusts the size of the data blocks according to the network conditions. This allows TCP to adapt to data transmission in different network environments.

UDP has no limit on packet size, it can send data of any size. But in actual use, the packet size is usually limited to the maximum MTU (Maximum Transmission Unit) of the network transmission.

To sum up, there are differences between TCP and UDP in terms of reliability, speed, connectivity and packet size. The choice of which protocol to use depends on specific application scenarios and requirements. If reliable and ordered data transmission is required, TCP should be selected. If you have high requirements for real-time transmission and can tolerate a certain amount of data loss, you can choose UDP.

The above is the detailed content of What are the differences between tcp and udp?. For more information, please follow other related articles on the PHP Chinese website!