At which layer does the UDP protocol work?

The Internet protocol suite supports a connectionless transport protocol called the User Datagram Protocol (UDP). UDP provides a way for applications to send encapsulated IP datagrams without establishing a connection.​ (Recommended learning: phpstorm)

The Internet's transport layer has two main protocols, which complement each other. Connectionless is UDP, which does little in particular except give applications the ability to send packets and allow them to architect their own protocols at the required level. The connection-oriented one is TCP, which does almost everything.

UDP is the abbreviation of User Datagram Protocol. The Chinese name is User Datagram Protocol. It is a connectionless transport layer protocol in the OSI (Open System Interconnection, Open System Interconnection) reference model. It provides A simple transaction-oriented unreliable message transfer service, IETF RFC 768 [1] is the formal specification of UDP. The protocol number of UDP in IP packets is 17.

The UDP protocol is used to process data packets like the TCP protocol. In the OSI model, both are located at the transport layer, which is the upper layer of the IP protocol.

UDP has the disadvantage of not providing data packet grouping, assembly, and inability to sort data packets. In other words, after a message is sent, it is impossible to know whether it has arrived safely and completely.

UDP is used to support network applications that need to transmit data between computers. Numerous client/server network applications, including network video conferencing systems, require the use of UDP protocol.

The UDP protocol has been used for many years since its inception. Although its initial glory has been overshadowed by some similar protocols, UDP is still a very practical and feasible network transport layer protocol even today.

Many applications only support UDP, such as multimedia data streams, which do not generate any additional data and will not retransmit even if damaged packets are known.

When the emphasis is on transmission performance rather than transmission integrity, such as audio and multimedia applications, UDP is the best choice. UDP is also a good choice when the data transmission time is so short that the previous connection process becomes the main body of the entire traffic.

UDP is a connectionless transport layer protocol in the OSI reference model. It is mainly used for transmissions that do not require packets to arrive in sequence. The checking and sorting of packet transmission sequences are completed by the application layer, providing A simple transaction-oriented unreliable messaging service. UDP protocol is basically the interface between IP protocol and upper layer protocol. The UDP protocol is suitable for multiple applications running on the same device.

UDP provides connectionless communication and does not guarantee the reliability of transmitted data packets. It is suitable for transmitting a small amount of data at a time. The reliability of UDP transmission is responsible for the application layer. Commonly used UDP port numbers are: 53 (DNS), 69 (TFTP), and 161 (SNMP). UDP protocols include: TFTP, SNMP, NFS, DNS, and BOOTP.

The above is the detailed content of At which layer does the UDP protocol work?. For more information, please follow other related articles on the PHP Chinese website!