The main topology of local networks. Types of local networks and their device
Local network is an important element of any modern enterprise, without which it is impossible to achieve maximum However, to use the capabilities of networks at full capacity, you need to properly configure them, taking into account that the location of the connected computers will affect the performance of the LAN.
Concept of topology
The topology of local computer networks is the location of workstations and nodes relative to each other and options for connecting them. In fact, this is the LAN architecture. The placement of computers determines the technical characteristics of the network, and the choice of any kind of topology will affect:
- Varieties and characteristics of network equipment.
- Reliability and scalability of LAN.
- The way to control the local network.
There are many such options for the location of work nodes and ways to connect them, and their number increases in direct proportion to the increase in the number of connected computers.The main topology of local networks is a "star", "tire" and "ring".
Factors to Consider When Choosing a Topology
Before finally determining the choice of topology, it is necessary to take into account several features that affect the performance of the network. Based on them, you can choose the most appropriate topology, analyzing the advantages and disadvantages of each of them and correlate these data with the conditions available for installation.
- Efficiency and operability of each of the workstations connected to the LAN. Some kinds of local network topology depend entirely on this.
- Serviceability of equipment (routers, adapters, etc.). Breakdown of network equipment can both completely disrupt the work of the LAN and stop the exchange of information with one computer.
- The reliability of the cable used. Damage to it violates the transmission and reception of data across the entire LAN or on one of its segments.
- Cable length limitation. This factor is also important when choosing a topology. If the cable is available a little, you can choose a method of location in which it will need less.
About the star topology
This type of workstation location has a dedicated center - a server to which all other computers are connected. It is through the server that data exchange processes occur. Therefore, its equipment must be more complex.
- The topology of local networks "star" compares favorably with other complete lack of conflicts in the LAN - this is achieved through centralized management.
- Breakdown of one of the nodes or damage to the cable will not have any effect on the network as a whole.
- Having only two subscribers, the main one and the peripheral one, allows to simplify the network equipment.
- The accumulation of connection points in a small radius simplifies the process of monitoring the network, and also makes it possible to increase its security by restricting access to outsiders.
- Such a local network in the event of a central server failure becomes completely inoperative.
- The cost of the "star" is higher than other topologies, since the cable is required much more.
Bus topology: simple and cheap
In this method of connection, all workstations are connected to a single line - a coaxial cable, and the data from one subscriber is sent to the rest in half-duplex mode.Topology local area networks of this type assume that there is a special terminator at each end of the bus, without which the signal is distorted.
- All computers are equal.
- The ability to easily scale the network even during its operation.
- Failure of one node does not affect the rest.
- Cable consumption is significantly reduced.
- Insufficient network reliability due to problems with cable connectors.
- The small productivity caused by division of the channel between all subscribers.
- The complexity of managing and detecting faults due to parallel-connected adapters.
- The length of the communication line is limited, because these types of local network topologies are used only for a small number of computers.
Characteristics of the ring topology
This type of communication involves the connection of the working node with the other two, data is received from one of them, and transmitted to the second. The main feature of this topology is that each terminal acts as a repeater, eliminating the possibility of signal attenuation in a LAN.
- Quickly create and configure this LAN topology.
- Easy scaling, requiring, however, termination of the network at the time of installation of the new node.
- A large number of possible subscribers.
- Resilience to overloads and the absence of network conflicts.
- The ability to increase the network to a huge size due to the signal relay between computers.
- Unreliability of the network as a whole.
- The lack of resistance to cable damage, therefore, usually provides for the presence of a parallel backup line.
- High cable consumption.
Types of local networks
The choice of LAN topology should also be made based on the type of LAN available. A network can be represented by two models: peer-to-peer and hierarchical. They are not very different functionally, which allows, if necessary, to move from one to the other. However, there are some differences between them.
As for the peer-to-peer model, its application is recommended in situations when there is no possibility of organizing a large network, but the creation of a communication system is still necessary. It is recommended to create it only for a small number of computers.Communication with centralized management is usually used in various enterprises to monitor workstations.
Peer to Peer Network
This type of LAN implies equality of each workstation, distributing data between them. Access to information stored on the site may be allowed or denied by the user. As a rule, in such cases, the topology of local computer networks "bus" will be most appropriate.
A peer-to-peer network implies the availability of workstation resources to other users. This means the ability to edit the document of one computer when working after another, remote printing and launching applications.
Advantages of peer type LAN:
- Ease of implementation, installation and maintenance.
- Small financial costs. This model eliminates the need to buy an expensive server.
- Network performance decreases in proportion to the increase in the number of connected work nodes.
- There is no unified security system.
- Availability of information: when you turn off the computer, the data in it will become inaccessible to others.
- There is no single information base.
The most commonly used LAN topologies are based on this type of LAN. It is also called "client-server". The essence of this model is that in the presence of a certain number of subscribers there is one main element - the server. This control computer stores all data and processes it.
- Excellent network performance.
- Unified reliable security system.
- One, the general for all, information base.
- Easy management of the entire network and its elements.
- The need for a special personnel unit - an administrator who monitors and maintains the server.
- Large financial costs for the purchase of the main computer.
The most frequently used configuration (topology) of a local computer network in a hierarchical model is the “star”.
The choice of topology (layout of network equipment and workstations) is extremely important in the organization of a local network. The selected type of communication should ensure the most effective and safe operation of the LAN. It is also important to pay attention to financial costs and the possibility of further expanding the network.Finding a rational solution is not an easy task, which is carried out through careful analysis and responsible approach. In this case, correctly chosen topology of local networks will ensure maximum efficiency of the entire LAN as a whole.