What is the current topology of local area networks?

The current topology structures of local area networks are generally bus, ring, and star structures, and other topologies are mostly derived or combined from these three structures. There are two types of cyclic structures, namely single-ring structure and double-ring structure. Token ring is a typical representative of a single-ring structure, and Fiber Distributed Data Interface (FDDI) is a typical representative of a dual-ring structure.

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

Network topology refers to the physical layout of various devices interconnected using transmission media. In order for computers and other devices in the network to be interconnected, they need to be connected in a certain structural manner. This connection method is called "topology". In layman's terms, it is how these network devices are connected together. Common network topologies mainly include: bus structure, ring structure, star structure, tree structure and mesh structure.

Local Area Network (LAN) is a private network that generally exists within a building. Local area networks are widely used to connect personal computers and consumer electronic devices, allowing them to share resources (such as servers, printers) and exchange information. When a LAN is used in a company, it is called an Enterprise Network.

LANs are generally divided into two types: wired LANs and wireless LANs. Wired LANs use a variety of different transmission technologies. Most of them use copper wire as the transmission medium, but some use optical fiber. Typically, wired LANs operate at rates between 100 Mbit/s and 1 Gbit/s, with very low latency (microseconds or nanoseconds) and few errors. Newer LANs can even operate at rates up to 10 Gbit/s.

Common LAN topologies can be divided into: bus type, ring type, and star type. Most of the remaining topological structures are derived or combined from these three structures.

Bus-type structure

The bus-type structure uses a single communication line (bus) as a public transmission channel, and all nodes pass the corresponding The interface is directly connected to the bus and data is transmitted through the bus. For example, computers or other shared devices that make up a network are connected on a single cable, as shown in Figure 1. Because a single cable supports only one channel, computers and other shared devices connected to the cable share all of the cable's capacity. The more devices connected to the bus, the slower the network sends and receives data. [4]

Bus-type networks use broadcast transmission technology. All nodes on the bus can send data to the bus, and the data is propagated along the bus. However, since all nodes share the same common channel, only one station is allowed to send data at any time. When one node sends data and propagates on the bus, the data can be received by all other nodes on the bus. After receiving the data, each site analyzes the destination physical address and then decides whether to receive the data. Thick and thin coaxial cable Ethernet are typical representatives of this structure.

Ring structure

In the ring structure, each workstation has the same status. They are connected to each other sequentially to form a closed ring. Data can be single in the ring. Transmit in either direction or in both directions. The ring topology has a simple structure and a certain transmission delay. However, the communication lines between each station in the ring and the connecting station will become a bottleneck for network reliability. A communication failure at any station in the ring will cause network paralysis.

There are two types of cyclic structures, namely single-ring structure and double-ring structure. Token ring is a typical representative of a single-ring structure, and Fiber Distributed Data Interface (FDDI) is a typical representative of a dual-ring structure.

Star structure

Each node in the star structure has a point-to-point link with the central node (public central switching equipment, such as switches, hubs, etc. ) are connected, as shown in Figure 3. If a node in a star network sends data to another node, it first sends the data to the central device, and then the central device forwards the data to the target node. The transmission of information is realized through the storage and forwarding technology of the central node, and can only communicate with other nodes through the central node. Star network is the most commonly used topology in local area networks.

If you want to read more related articles, please visit PHP Chinese website! !

The above is the detailed content of What is the current topology of local area networks?. For more information, please follow other related articles on the PHP Chinese website!