The three elements of network protocols and their meanings: 1. Semantics, explaining the meaning of each part of control information; 2. Syntax, the structure and format of user data and control information, and the order in which data appears; 3. , timing, a detailed description of the sequence of events. To put it simply: semantics represents what to do, syntax represents how to do it, and timing represents the order in which to do it.
Network protocol is a collection of rules, standards or conventions established for data exchange in a computer network.
For example, a microcomputer user in the network communicates with a mainframe operator. Since the two data terminals use different character sets, the commands entered by the operators do not recognize each other.
In order to enable communication, it is stipulated that each terminal must first convert the characters in its own character set into the characters in the standard character set before entering the network for transmission. After reaching the destination terminal, it is then converted into the terminal character set. character of. Of course, for incompatible terminals, in addition to changing the character set characters, other characteristics such as display format, line length, number of lines, screen scrolling method, etc. also need to be changed accordingly.
The three elements of the network protocol and their meaning
The network protocol is composed of three elements:
(1) Semantics. Semantics is the interpretation of the meaning of each part of the control information. It specifies what control information needs to be sent, as well as the completed actions and responses.
(2) Grammar. Syntax is the structure and format of user data and control information, as well as the order in which the data appears.
(3) Timing. Chronology is a detailed description of the order in which events occur. (Also known as "synchronization").
People vividly describe these three elements as: semantics represents what to do, syntax represents how to do it, and timing represents the order of doing it.
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