The choice of topology is often closely related to the choice of transmission media and the determination of media access control methods. When choosing a network topology, the following main factors should be considered:

(1) reliability. Improve the reliability as much as possible to ensure that all data streams can be accurately received; The maintainability of the system should also be considered to make fault detection and fault isolation more convenient.

? (2) expenses. When building a network, the channel cost and installation cost suitable for a specific application should be considered.

? (3) flexibility. What needs to be considered is that when the system is expanded or modified in the future, the network topology can be easily reconfigured, and the deletion of the original site and the addition of new sites can be easily handled.

? (4) Response time and throughput. Provide users with the shortest possible response time and maximum throughput.

The term "topology" is borrowed from geometry. Network topology refers to the network shape or its physical connectivity. Network topology mainly includes star topology, bus topology, ring topology, tree topology, hybrid topology and mesh topology.