What are the main elements of network protocols?

The main elements of the network protocol are: 1. Semantics; explaining the meaning of each part of the control information. 2. Grammar; 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.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

Network protocol is a collection of rules, standards or conventions established for data exchange in computer networks.

Peer entities usually refer to information units at the same level in the computer network architecture. The general system network protocol includes five parts: communication environment, transmission service, vocabulary, information encoding format, timing, rules and procedures. In 1969, when the U.S. Department of Defense established the ARPA Computer Network, the earliest network, it issued a set of military standards for computer communication protocols. It included five protocols. It is customary to use TCP and IP as this set of protocols. general name.

Main elements of network protocols

(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.

Hierarchical structure

Due to the complexity of the connections between network nodes, when formulating a protocol, complex components are usually decomposed into some simple components and then combined stand up. The most commonly used composite technology is the hierarchical approach. The hierarchical structure of the network protocol is as follows:

(1) Each layer in the structure stipulates clear service and interface standards.

(2) Treat the user’s application as the highest layer

(3) Except for the highest layer, each layer in the middle provides services to the upper layer and at the same time to the lower layer user.

(4) The physical communication line is regarded as the lowest layer. It uses parameters transmitted from the highest layer and is the basis for providing services.

Commonly used protocols

TCP/IP protocol:

TCP/IP (Transport Control Protocol/Internet Protocol, Transmission Control Protocol/Internet Protocol) The history should be traced back to the predecessor of the Internet - the ARPAnet era. In order to realize the interconnection between different networks, the U.S. Department of Defense developed the TCP/IP architecture and protocols from 1977 to 1979. TCP/IP is composed of a set of multiple sub-protocols with professional purposes, including TCP, IP, UDP, ARP, ICMP, etc. TCP/IP has developed rapidly due to its advantages such as low implementation cost, secure and reliable communication between multiple platforms, and routability, and has become a standard protocol in the Internet. In the 1990s, TCP/IP has become the preferred protocol in local area networks. In the latest operating systems (such as Windows 7, Windows XP, Windows Server 2003, etc.), TCP/IP has been installed as the default communication protocol.

NetBEUI:

That is NetBios Enhanced User Interface, or NetBios Enhanced User Interface. It is an enhanced version of the NetBIOS protocol and has been adopted by many operating systems, such as Windows for Workgroup, Win 9x series, Windows NT, etc. The NETBEUI protocol is useful in many situations and is the default protocol for operating systems before WINDOWS98. The NetBEUI protocol is a short and concise broadcast protocol with high communication efficiency. It does not require any settings after installation and is particularly suitable for transmitting data in "Network Neighborhoods". Therefore, it is recommended that in addition to the TCP/IP protocol, computers in small LANs can also be equipped with the NetBEUI protocol. Another thing to note is that if a WINDOWS98 machine with only the TCP/IP protocol installed wants to join the WINNT domain, the NetBEUI protocol must also be installed.

IPX/SPX protocol:

It is originally a protocol developed by Novell specifically for use in NetWare networks, but it is also very commonly used - most online games support the IPX/SPX protocol, such as StarCraft, Counter-Strike, etc. Although these games can also be connected through the TCP/IP protocol, it is obviously more troublesome to use the IPX/SPX protocol because no settings are required at all. Apart from this, the IPX/SPX protocol does not seem to be very useful in non-LAN networks. If you are determined not to play games online in a local area network, then this agreement is dispensable.

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