Topology of computer networks

The concept of a computer network implies the following definition. A network is a collection of objects that is formed by devices that transmit and process data. The International Organization for Standardization computer network is defined as a sequential bit-oriented system for transferring information between independent but interconnected devices.

The architecture of computer networks is such that networks usually occupy a certain territory, therefore, they are most often divided according to the territorial character. There are local, regional and global networks.

The advantages that the networking of personal computers give most often include the ability to share resources, share data, share software, share the resources of the processor, the ability to organize a multi-user mode.

Different characteristics of the networks make it possible to create various classifications of computer networks. These attributes include the topology of computer networks, their purpose, the list of services provided, management principles (can be centralized and decentralized), switching methods, access methods, transmission medium types, data transmission speed, and so on.

Let us dwell in more detail on such an important concept as the topology of computer networks. In any computer network, each workstation is physically connected to other communication channels. The connection is made according to a certain structure, which was called the topology of computer networks. Thus, the topology of computer networks is inherently a description of physical connections in the computer network, which indicates specific workstations that are able to communicate with each other. From what type the topology of computer networks is characterized, the level of productivity, operability and reliability of operation of workstations being combined into the network depends, as well as the time interval required to access the file server. In addition, the topology directly affects the access method to the network, which will be applied.

To date, there are five types of computer network topologies, but three have spread widely: bus topology, ring topology, topology of the "star" type.

The bus topology assumes that all network nodes will be connected to a peer- to -peer network using a single cable. The termination of the cable should be the resistive load. The only cable supports a single data channel . In the bus topology, the cable is called the bus. Networks built on the bus topology are created on the basis of a coaxial cable.

The ring topology has found its implementation in simple peer-to-peer computing networks. All workstations, according to this topology, are connected to their two nearest neighbors. If you consider the general scheme of connection in a network created by the ring topology, you can see something resembling a ring. Data in such networks can be transmitted in a single direction, and all workstations work as repeaters that receive and respond to packets addressed to them, and then transmit the remaining data packets to the next workstation that is located "downstream".

Local networks, built according to the star topology, were the most widely used today. In such networks, data to devices diverges from a common point represented by a hub, router, or switch. If you imagine a concentrator as the center of a star, then the divergent ones from it will resemble rays - hence the given topology and got its name. The main advantage of the star topology in comparison with the ring topology is the possibility of implementing the right of independent access to the network provided to any device. In this case, each device is able to access the transmission medium, regardless of other devices located on the network.