Network topology is the physical or logical way the network is designed and organized mapping as a communication structure used by computers that form a network to exchange data.
What is Computer Network Topologies, and What Are Its Types?
A network topology is created by interconnected nodes, and its structure can be expanded by connecting each node to the next node. The way the nodes are physically connected forms the topology, and there are also different standardized topologies applicable to the TCP protocol, with each node having its own characteristics.
The topology of a network refers to the geometric arrangement of devices connected to it. The most common topologies from past to present; It is Bus, Ring, Star, Tree, and Mesh.
The bus topology is similar to the star topology but all devices are connected through a single shared transmission medium. All nodes communicate on a common bus circuit, and the information sent from one computer to another transfer data directly or indirectly with a controller that directs the data to the correct destination.
In this topology, data transfer travels through the cable in both directions at a rate of about 10/100 Mbps, and there is a terminator at both ends. Multiple computers can be connected to the bus topology, but if one computer fails, communication is maintained, but if the bus fails, the entire network is interrupted.
Normally, the type of wiring used in network structures can be coaxial, twisted pair, or fiber optic, but in a bus topology, each computer can communicate by connecting to a common network cable segment.
The network segment is configured as a linear bus, a long cable that goes from one end of the network to the other, to which each node of the network is connected. So the wiring structure can run through the floor, walls, ceiling, or several places.
In a ring topology, communication takes place through a token that acts as a passing postman collecting and delivering information packets, thus preventing information loss from collisions.
With a double ring topology (token ring), sending data in both directions can be configured. This configuration creates fault tolerance and if one of the rings fails of any kind, the active ring takes over the function of both.
The ring network has only one inbound and one outbound connection of each node, so each station has a receiver and a transmitter acting as a translator that transmits the signal to the next station.
The network structure is simple and straightforward.
The network is easy to configure.
Data flow is easy.
It has a limited channel length.
As the network grows and new nodes are added, channel efficiency decreases.
Data transfer is easy but slow.
Star topology typically has an active hub with means of echo-related issues in data transfer and is often used for local networks. Routers, switches, or hubs are generally used in this network structure.
The central node of the star topology becomes the router, switch, or hub device through which all packets pass. All nodes can only send and receive data through the central node.
If a problem occurs in the connection of any node to the central node, that node is isolated from the others. In this topology, hub devices were used widely in the past, but nowadays switches are more widely used since switches were more intelligent network devices and were developed.
If communication is established through a switch, which is only one central device, the device to be purchased must be of good quality and stable, since the device will be loaded too much.
It has the necessary tools to prevent potential problems in the network.
If a computer is disconnected or its cable is broken, only that computer is out of the network and other computers can continue to communicate.
Adding a new computer to the network structure is simple and easy.
Finding faults that may occur is very easy in terms of time.
All nodes can communicate with each other quickly.
Network maintenance or upgrade processes are less expensive than bus and ring topology.
When the central node fails, the entire network is disconnected.
The cost is slightly more expensive as it requires more cables than a bus or ring topologies.
The cable is pulled from the hub or switch to each computer independently.
Another disadvantage is that when an attack is made on the network, all devices connected to the central node remain vulnerable.
Tree topology consists of a series of interconnected star networks, except that they do not have a central node. Generally, a single cable connection from switch to switch is sufficient to create a structure like a separate network that includes other nodes. This allows the network to be expanded like branches of a tree.
It is similar to the bus topology, but the failure of a node does not mean that data communication is interrupted and the same communication channel is shared.
Both the tree and the star topology work like the bus structure when the interconnect node is in the broadcast mode because the information is completed by passing through other branches from a central point to all stations depending on the characteristics of the branches.
In this network structure, interference may occur between signals when two or more stations transmit at the same time since there is a shared transmission medium between many stations.
In short, tree topology can be viewed as a combination of several star topologies and expressed as a collection of star networks arranged in a hierarchy.
When transmitting signals, the central hub increases power and increases the distance the signal can travel.
More devices can be connected thanks to the inclusion of secondary hubs or switches.
It allows prioritization and isolation of communications from critical computers.
It is widely used as it is supported by a large number of software and hardware vendors.
One of its main disadvantages is that it requires more cables.
The size of each section is determined by the cable structure used.
If the central node collapses, the whole partition crashes with it.
It is more difficult to configure and takes time.
Mesh topology is a network topology where each node is connected to all nodes and has the ability to send messages in different ways from one node to another.
If redundant paths are configured in this network structure, there cannot be any interruption in data communication. Therefore, this network structure is created in large networks and locations where important data is processed, and possible problems in data transmission are minimized thanks to the additional paths of each server in the environment to all other servers.
When a computer fails on the network, the topology continues to work, because the rest of the computers do not pass through this point but pass through alternative routes.
It is a very reliable network structure.
In case of possible switch failures that may occur, data is sent through alternative ways.
When a node in the network fails, the network continues to operate.
Since the amount of cable used for redundant roads is high, its cost is higher than other topologies.
The network is more difficult to manage.
It may take some time to find possible faults on the network.
It is more difficult to configure because the wiring processes are longer.