Directory
Data Unit
Features
Implementation
Requirements
UDP Header Format
Client illustration for sending UDP requests
Data Unit
The data unit protocol transmitted by UDP is UDP packets or user datagram.
Features
UDP is connectionless, that is, no connection is required before sending data.
UDP uses the best effort to deliver, that is, it does not guarantee reliable delivery, and does not use congestion control.
UDP is message-oriented. UDP has no congestion control and is suitable for multimedia communication.
UDP supports one-to-one, one-to-many, multiple-to-one, and multiple-to-many interactive communication.
The UDP header has a low overhead and only eight bytes.
Implementation
The packet sent by the sender UDP to the application is delivered to the IP layer after the header is added. the packets sent by UDP to the application layer are not merged or split, but the boundary of these packets is retained.
The maximum number of packets sent from the application layer to UDP. UDP sends one packet at a time.
The UDP User Datagram sent by the receiver to the IP layer is delivered to the upper-layer application process intact after the header is removed, and a complete packet is delivered at a time.
Requirements
The application must select packets of the appropriate size.
UDP Header Format
Note:
- User Datagram UDP has two fields: Data Field and header field. The header field contains eight bytes and consists of four fields. Each field is two bytes.
- During the calculation test, the "pseudo Header" and UDP User Datagram are temporarily connected. The pseudo header is only used for calculation test and
Illustration:
Client illustration for sending UDP requests
(Transport Layer) UDP protocol