In option C, there are generally three topologies of local area network: star, bus and ring. Item A, the network structure that can paralyze the whole network as long as one node fails is a ring structure; Item b has a mixed topology; Item D, the ring topology saves network cables compared with other structures.

The topological structure of computer network refers to the physical composition of nodes and lines formed by computers or devices on the Internet and transmission media. There are two kinds of nodes in the network: one is the transit node used to convert and exchange information, including node switches, hubs and terminal controllers; The other is an access node, which includes a computer host and a terminal. Lines represent various tangible and intangible transmission media.

Each network structure consists of nodes, links and paths.

1, node: also called network unit, it is all kinds of data processing equipment, data communication control equipment and data terminal equipment in the network system. Common nodes are servers, workstations, hubs and switches.

2. Link: The connection between two nodes can be divided into two types: physical link and logical link. The former refers to the actual communication line, while the latter refers to the network path where logic works.

3. Path: refers to a series of nodes and links from the sending node to the receiving node, that is, a series of node-to-node chains established through the communication network.

Extended data:

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.

Common types:

The topological structure of computer networks mainly includes bus topology, star topology, ring topology, tree topology, mesh topology and mixed topology.

References:

Baidu Encyclopedia-Computer Network Topology Structure