The four stages are:
1. Multi-terminal online system centered on single-computer computing: In the 1950s and 1960s, computer networks entered the terminal-oriented stage, with the host as the center, and data communication with remote terminals through computers.
Features: The host is not only responsible for data processing but also for communication processing. The terminal is only responsible for receiving display data or providing data for the host. Easy to maintain and manage, data consistency number, but the host load is large, the reliability is poor, and the data transmission rate is low.
2. The birth of the packet switching network: In the mid-1960s, several computers were connected to each other to form a system, that is, using communication lines to connect multiple computers to realize the communication between computers. This is the second stage of the development of computer networks is the network stage centered on packet switching networks.
At this stage, there are mainly two landmark achievements: It is proposed that the packet switching technology forms the prototype of the TCP/IP protocol. In this period, the host is only responsible for data processing, and the data communication is completed by the packet switching network.
3. Standardization of network architecture: From the late 1970s to the early 1980s, microcomputers have been widely used. In order to meet the needs of office automation, various agencies, enterprises and institutions urgently require that they own a large number of microcomputers. Computers, workstations, small computers, etc. are connected to achieve the purpose of resource sharing and mutual information transmission.
However, the networking between computers in this period is conditional. Only computers produced by the same manufacturer can exist in the same network, and computers produced by other manufacturers cannot be accessed. This situation hinders the development of network interconnection and promotes the emergence of network standardization. In 1984, ISO published the OSI/RM-development system interconnection reference model, based on ARPANET, which formed the TCP/IP network architecture, which was popular all over the world.
4. High-speed computer networks for global interconnection: After the 1990s, with the emergence of digital communications, computer networks have entered the fourth stage of development. Its main characteristics are integration, high speed, intelligence and globalization.