Decrypting LANs: Small enclaves in the online world

Local area network has always been one of the focuses of people's attention. Its range is usually within several kilometers, and its convenient installation, cost savings, and ease of expansion make it widely used in various office spaces. LAN can not only realize file management, software sharing, printer sharing and other functions, but also effectively protects the security of data and ensures the stable operation of the network by maintaining network security.

The classification of local area networks mainly uses the following methods:

Classification by topology: including bus type, ring type, star type and hybrid topology structure, the local area network is divided into different types.

Classified by transmission media: including coaxial cables, twisted pairs, optical cables and other media, LANs can be divided into different types.

Classification according to the method of accessing the transmission medium: using different media access control methods, such as Ethernet, token network, FDDE network, ATM network, etc.

Classification by network operating system: According to the network operating system used, such as Netware network, 3+OPEN network, Windows NT network, LAN Manager network, VINES network, etc.

Other classification methods: Classification based on data transmission speed, information exchange method, etc.

The working principle of LAN communication involves the physical layer, data link layer, Internet layer, transport layer and application layer.

- Physical layer: Realizes the physical connection between computers, uses binary encoding, and completes data transmission through underlying hardware facilities.

- Data link layer: controls information transmission and routing, divides data into data blocks, and assigns control identifiers and error control information.

- Internet layer: To implement data transmission and routing, IP addresses are required.

- Transport layer: Establish a reliable information transmission channel. The main protocols are TCP and UDP, which respectively realize reliable transmission and provide services for user data.

- Application layer: handles applications, including common protocols and services such as FTP, SMTP, Telnet, HTTP, etc.

Finally, thank you all for your reading and support. Through this article, I hope you will have a deeper understanding of LAN. Have a nice day everyone.