# Network Topology and its Types

A network's topology is, in its most fundamental sense, the arrangement of the ways in which its nodes and workstations are connected to one another.

The choice of topology for a network cannot be made in a vacuum because it has an impact on both the selection of media and the access method that is put into use.

When making this determination, a number of different considerations are taken into account. This is a list of some of the most significant of which are as follows:

• Cost: One should strive to reduce the amount of money spent on installing a network in order to maximize its cost-effectiveness. To achieve this goal, it is possible to make use of well-understood media and, to a lesser extent, to reduce the distances that are involved.
• Flexibility: The topology of the network ought to be designed in such a way that it is simple to reconfigure in light of the fact that the office layout, including the arrangement of furniture and internal walls, is frequently subject to change. This requires relocating the nodes that are already there and adding new ones.
• Reliability: Failure in a network can manifest itself in one of two ways, as follows: The first error, which is referred to as "an individual node or workstation can malfunction," is not a critical error. The second problem, which is a more serious issue, is that "the network itself fails to operate."

## Network Topology Types

Therefore, picking the appropriate topology is required in order to establish a network that is economical, adaptable, and dependable. The following is an outline of the topologies that are covered in this article for your reference.

Now, let's move on to providing a succinct explanation of each of the enumerated types of topology, beginning with the "point-to-point link."

In its most fundamental form, a point-to-point, or P-P, link is dependent upon the performance of two functions: transmit and receive.

The fact that each station in a point-to-point network only receives a signal from a single transmitter and that each transmitter only sends its signal to a single receiver is the primary distinguishing feature of this type of network.

It is possible for the transmit and receive operations to take place over separate wires, which results in improved performance; alternatively, they can take turns using a number of different techniques while taking place over the same wire.

## Network Topology: Star Topology

One of the more common topologies used these days is the star topology. In this configuration, all of the devices are linked to a centralized device. Hubs, or more commonly known as switches, are centralized devices.

In this configuration, each device that needs to switch is provided with its own cable to connect it, and all communication is routed through a single, centralized device (switch or hub).

The star topology is utilized in the majority of the currently operating information networks that include data processing or voice communications. The most common example of this is found in IBM 370 installations. In this scenario, a number of different 3270 terminals are linked to either a host system or a terminal controller.

### The Benefits of Using a Star Topology

The following is a list of some of the primary benefits that come with using star topology:

• Within the framework of star topology, it is simple to install new systems in place of older ones. This does not have any effect on the network as a whole.
• In the event that a cable fails in a single location, the impact is confined to the user of that particular cable or computer.
• When using a star topology, troubleshooting and problem detection are made to be extremely easy.

### The drawbacks of using a star topology

The following is a list of some of the most significant drawbacks associated with utilizing the star topology:

• In a star topology, every computer system needs a certain amount of cable in order to be connected to a centralized device; to put it another way, there is a need for more cable in a star topology.
• If a centrally located device in a star topology fails, which it cannot do in a short amount of time, then there is a single point of failure in the system. It is extremely challenging to find a solution to this problem given that each and every device, as well as each and every computer, requires its own unique cable.

## Network Topology: Bus or Linear Topology

The bus topology uses a backbone cable or drawing, and all devices are connected with this.

To put it another way, the bus topology is comprised of a single length of the transmission medium, which is typically coaxial cable. The various nodes are connected to this single length of the transmission medium.

The transmission that comes from any station is able to be received by all of the other stations because it travels the entire length of the bus in both directions. "Terminators" are located at each end of the bus, and their job is to pull the signal off of the bus after they have received it.

A terminator is connected to the T-connectors that are used in the bus top, and the bus top itself is terminated.

This method was at one time utilized in the construction of both a thin net and a thick net, respectively known as 10 base-2 and 10 base-5, and it enjoyed a great deal of success. For this particular method, coaxial cable was the medium of choice.

The following is a list of some of the primary benefits of utilizing the bus topology:

• Because there is only a requirement for a single cable, it is very simple to set up. Because of this, it makes use of less cable and has a more straightforward wiring layout.
• In addition, bus topology does not call for the utilization of any networking or specialized hardware.
• LAN cards, t-connectors, and terminators are the only components necessary.
• A bus network that is already in place allows for the connection of additional nodes at any point along its length. By adding additional segments that are connected by a repeater, it is possible to accomplish more extensive additions. Repeaters are a type of signal amplifier.

The following is a list of some of the primary drawbacks associated with using the bus topology:

• The functionality of the entire network is disrupted in the event that a cable is severed or a break in the cable itself takes place anywhere within a bus topology. After that, finding a solution to the problem will be difficult.
• When using a bus topology, if you want to add a new computer to replace an older one, the network will stop functioning once the new computer has been added to replace the older one.
• Every node in the network has an unbroken line of communication with the centralized bus. Because of this, it is necessary for each node to implement a method for determining who is permitted to use the network at any given time.

## Network Topology: Ring or Circular Topology

In ring topology, our devices are connected together in a circular fashion. Every node in a ring topology is connected to its immediate neighbours in an exact ratio of two to one. After receiving data from one of the neighbouring nodes, it is then transmitted to the next node in the network.

As a result, data can only move in a single direction, which is clockwise around the ring, from node to node. When it has completed its journey through all of the nodes, it goes back to the node that sent it, and that node deletes it.

It is essential to understand that when data is passed through rather than traveling past each node, the signal has the opportunity to be amplified before being repeated on the channel that leads outside.

The technology uses the ring topology:

• FDDI
• SONET
• Token Ring

The use of the ring topology has a number of benefits, some of which are listed below:

• When contrasted with a star topology, the amount of cabling required for a ring topology is on par with that of a bus topology and significantly less than that of a star topology. It indicates that there will be a need for fewer connections, which will result in an increase in the network's reliability. In a nutshell, the cable length can't be too long when using a ring topology.
• It is not necessary to designate space in the building for wiring closets because there is only one cable connecting each node to its immediate neighbours. In a nutshell, there is no need for any wiring closet space when using a ring topology.
• The utilization of optical fibres makes it possible to achieve extremely high transmission speeds. Optical fibres make an excellent transmission medium, and the fact that traffic on a ring road moves in only one direction makes this a straightforward possibility. In a nutshell, the ring topology is appropriate for use with optical fibres.

### The Drawbacks of Using a Ring Topology

The following is a list of some of the drawbacks associated with employing the ring or circular topology:

• A data transmission on a ring begins at the sender and travels around the ring, stopping at each connected node before arriving back at the sender. The entire network is considered to be inoperable if even a single node is unable to pass the data through itself. Until the faulty node is removed from the ring, no traffic will be able to move through the network. The failure of a node in a ring topology results in the failure of the network.
• The fact that the failure of one node affects all of the others has significant repercussions for the process of fault diagnosis. It is possible that it will be necessary to inspect a number of neighbouring nodes in order to identify the problematic node. In addition to that, the incorporation of diagnostic facilities into each node might be required for this operation. In ring topology, fault diagnosis can be challenging due to the nature of the topology.
• It is not possible to disable a portion of the ring while maintaining the functionality of the vast majority of it in its normal state. In nutshell, it's difficult to reconfigure a network when it's set up in ring topology.

## Network Topology: Tree Topology

The bus topology has several variations, one of which is the tree topology.

The shape of the network in tree topology is that of an upside-down tree, with the central root branching and sub-branching to the extremities of the network. This shape is called an inverted tree.

Transmission happens in the same way that it does in the bus topology when it's implemented in a tree topology. There is no need to remove any packets from the medium in either scenario because the terminators will pick up any signal that reaches the end of the medium and process it accordingly.

Applications that have a flow of data and control that is hierarchical are the ones that benefit most from using the tree topology. The tree topology is considered a hybrid topology due to the fact that it is a modification of a pure network topology known as the bus topology.

## Network Topology: Graph Topology

The nodes in a graph are connected to one another in an arbitrary fashion using graph topology.

In graph topology, a link between two or more nodes may or may not connect the nodes. It's possible that there are multiple links as well.

In graph topology, it is not essential for every node to have an associated connection with one another. On the other hand, if there is a way to get from one node to another using one or more links, the graph is referred to as a connected graph.

## Network Topology: Mesh Topology

When using a mesh topology, each node is connected to more than one other node. This creates a backup path in the event that the host becomes unavailable or cannot handle the traffic. The P-P network can be thought of as an extension of the mesh topology.

Because it provides a great deal of flexibility in terms of backup, routing, and passing through, the mesh topology is ideally suited for use in long-distance networking. The WAN has an unhealthy obsession with the mesh topology.

The wiring and mesh topology are overly complicated due to the fact that additional cables are required when we connect all of the devices to all of the other devices in the system.

## Network Topology: Fully Connected

A network's hosts are all directly connected to one another. That is, if each host has a direct link, the network is said to be fully connected. This characteristic is known as "full connectivity."

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