Advantages and Disadvantages of Star Topology
The physical arrangements of the nodes in a network can be described as the network's physical topology. The nodes in the networks can be represented in several ways. Some examples of physical topologies are:
This tutorial will discuss the advantages and disadvantages of star topology in computer networks.
Star topology is sometimes also referred to as the star network. In this physical arrangement of the nodes, each node or device in the network is linked with a central unit called a hub. This arrangement is used frequently for configuring computer networks. It is one of the most popular network topologies. Thus, all the nodes are connected to a single central unit. The equipment arrangement is similar to a star; therefore, it is referred to as the star topology.
Since there is no direct link between any nodes in the star topology, that why, unlike mesh topology, it is not possible to communicate directly between different devices in this network. All the communication between any node in star topology is performed using a hub. The user end devices or peripheral nodes act as clients in the network, while the central equipment through which all the peripheral nodes are connected acts as the server in the network. A coaxial cable or RJ-45 wire establishes a connection in the star topology. Similar to a bus topology, it is very simple to establish the star topology. It is pretty straightforward to set up.
Various places implement star topology networks. Some places that use this topology are Airports, Hospitals, banks and other organizations requiring a centralized management unit. The user can also use a switch as a central device instead of a hub. Since, in this arrangement, all the nodes are connected with a central unit without having any other direct link, there is a very high dependency on the central device in the star network. The whole computer network's communication fails if the network's central unit malfunctions.
Advantages of Star Topology
There are several advantages of using star topology to connect the nodes in your computer network. Some of these advantages are mentioned below:
1. High Fault Tolerance
In star topology, only a single node is affected when there is a NIC failure or the link between the node, and central equipment is damaged. Since all the nodes have an independent connection to the central unit, it provides an advantage to the user in case of node failure in the network. There is a single connection between the node and the central unit.
However, this means that every node in the network requires a separate connection; therefore, this structure is relatively more expensive than other network topologies. But the cost issues are outweighed because of other additional advantages offered by the star topology.
The entire network can only be affected under one condition when the arrangement's central unit is compromised. Only in this case, the entire network fails altogether. It is a safe network and is not readily available to the general public. This is mostly used in organizations that have several nodes for connections. This topology is used in businesses of different sizes to support their various needs.
2. Highly Scalable
Sometimes, the user wants to add new devices to the network. When using star topology, adding new nodes to the network is relatively simple. It is a straightforward process to add a new addition to the existing network. The user only needs to connect the device to the central core using a direct cable. This provides an advantage to the user when they are required to connect several devices with a single core. This way, it is possible to add new devices to the network without disturbing the existing structure of the network. Both new and previously attached devices can gain benefits from their structure.
Since the whole network is dependent on the central unit as all the nodes in the network are connected or disconnected from the central unit. The user can simply maintain the productivity of the network by replacing the nodes that are no longer functioning properly. Therefore this network is highly scalable and easy to maintain.
3. Connecting several Types of Devices
Star topology is the best type of option available when the user wants to use several varieties of applications as nodes in the network. It allows the user to connect different types of devices to the network. Both the hub and the switch allow the devices to forward the data packets to several types of devices.
Therefore, it is mostly used in businesses that require connecting different types of equipment with a network. It allows them to link the computer, laptops, printers and other stations using a central core.
It also provides an option to increase the range of each device connected to the star topology. This can be done by using a server connected to the central hub. Furthermore, the user can easily link the whole office with this network configuration until each node in the office is compatible with the hardware and software of the central hub. It should also support the network connection used for communication and data transmission.
4. Lower possibility of Data Collision
In this network configuration, all the nodes are connected to the central core with a one-to-one connection by using a direct cable. It decreases the possibility of data collision in the network. It can also manage the situation when data collisions occur in the network and does not create bottlenecks. This means that compared to other network orientation designs, the performance of the star topology is relatively high. However, when the traffic is very high, there may be some instances where the network transmits the data very slowly.
5. Multiple Approaches
Another advantage of using a star topology is that the user can implement multiple approaches. This means the user can choose to implement the network by using an active hub, a passive hub or even a switch as the central core to use as the central core when designing a star topology network.
If the user decides to use a passive hub, then it won't require the modification time of the data packets. The signal from through the nodes with any intervention in the star topology network is built using the passive hub.
Furthermore, in addition to the responsibilities performed by the central equipment, a network built by using an active hub can perform certain additional functions.
If the user uses a switch as the central component for the star topology network, then the data packet will only be transmitted to the intended receiving node. The switch reads the destination address of data packets and sends it to the designated node only. An active hub in the star topology can also act as the repeater in the network.
6. Avoids point-to-point connections
The approach to connecting the nodes in star topology is more streamlined; therefore, it facilitates faster communication than in other topologies. Though, the other topologies may provide a higher level of reliability.
Star topology is more flexible and can be installed in the organization confidently. Since there is a central core through which all the nodes and devices are connected, the users need not worry about communication among the devices in the network. This network can be easily implemented regardless of the size of the business and gain advantages.
It allows the user to establish point-based connections. It supports uni-cast communication and provides a secure pathway to share the data in the network. Another benefit of using this topology is that by implementing this network, there is no risk of signal reflections. Thus, it helps to avoid point-to-point connections in the network.
7. User Friendly
The user can easily manage individual nodes in the network. It can be easily set up without disturbing the existing network. The nodes can easily be added or removed at any moment. It is easier to replace the malfunctioning units in the network. The user can also add new units to increase the productivity of the topology.
8. Centralized Network
Since the whole network depends on a central core, it is easier to monitor and manage it using a centralized management system such as a server, central computer, switch, or hub.
Disadvantages of Star Topology
We have discussed several benefits of the star topology, but there are certain disadvantages of using this topology as well. Some of these disadvantages are mentioned below:
1. Malfunctioning of the central component
Since all the nodes in the star topology are connected to the central core device, such as a hub or switch, the entire network is highly dependent on this device, making it the most important component of the network.
If the network's central equipment fails, it may disrupt the working of the entire network. The entire network fails with the central core. In this situation, the user can perform work on the nodes offline but won't use the network. There may be instances to lessen the possibilities of collaboration immediately. If the central component malfunctions for any reason, the user may require to consider replacing the complete central core, and that can be significantly more difficult.
2. Expensive Installation
It is costly to install, and as it requires a central core, extending the topology also requires purchasing additional cables for the new nodes and devices in the network. Since each device has to be connected to the core, so each requires a separate cable.
Still, the most expensive component of this topology is the requirement of additional equipment, such as Hubs or switches that can be used as the core. It also requires additional connectors and cables. Since, each device only requires a single connection to the core, designing this topology is very simple and is quite reliable too.
The expensive cost to establish this topology is why some small businesses search for other alternative topologies in the network.
Although this topology is more expensive than other topologies, it increases the productivity of the network and reduces the time to look down maintenance issues, which can save costs.
The downtime is also less in this network, as each node has a separate connection with the core if the user disconnects any of the nodes in the network. The cable may be compromised by frequently disconnecting and connecting the nodes to the network.
3. Need for additional Equipment
The primary requirement for setting up nodes in the star topology is the central core of the network. This can either be a switch to a hub. If you must implement several star topologies together, then a separate core will be required for each star network. This installation is quite expensive and can complicate the design of the network. It can also create several vulnerabilities in some star networks.
The user can simply change the primary communication tool by removing the multi-star installation's central hub. In this arrangement, not all the network nodes will have permission to access the central database. Still, they can establish communication with other nodes available in the network.
4. Impact on Mobility
Most people still use wire connections to establish a connection between different devices, even when the wireless star topology is available in modern times. When cables connect the network nodes, the cable's limited length limits the moment of these nodes. It is difficult to move the nodes. Users cannot move their workstations to stay productive as the network is stationary. Moreover, the user will have to move from the workstations whenever required to use other equipment connected to the network, such as a printer. The central hub is bound to a particular distance from the other nodes, reducing the productivity level over time as the user will have to move from their place to reach other nodes.
5. Challenging in attaching mobile devices
Generally, adding new devices to the star topology is simpler, but it can be difficult to add wireless devices such as smartphones and other mobile devices. Moreover, some personal computer does not allow them to connect to the star topology.
Most of the central hubs available do not have a port that allows them to connect the internet with the system. So, if the user wants to connect the nodes to the internet, they will have to rely on a Wi-Fi or cellular connection to stay online. This means it is relatively hard to collaborate on projects using the star network if the organizations have workers who work with their mobile phones or have remote offices.
If someone tries to connect with the LAN without having an inside connection will have several issues than the ones that use a cable connection to communicate outside of the organization.
6. Cables are prone to damage
The cable used to connect the nodes and the central switch or hub in the star network is prone to damage. Usually, the nodes are separated in the organization, and the central hub is located in a different room. Therefore, the cable responsible for connecting the peripheral devices in the network must go under walls, through the walls or pass other obstacles when establishing the network.
Moreover, when the weather of the surroundings changes, it may also impact the performance of the wire or cable if the LAN is required to be installed on the external building. This can make it difficult to find the damage in the wire. This hugely impacts the reliability of the star topology. Damage to the wires connecting the nodes and core can occur for various reasons. The damage in the wires can be reduced by adding a protective layer. The user can increase the strength of the wire by bundling the wires.
7. Highly Dependent on Central Core
The entire network depends on the central core, such as a hub or switch. If the central core of the star topology fails, then the entire network of nodes fails with it. Each node in the network is dependent on the central device to communicate with each other. This is the major disadvantage of the star network, and that's why it is necessary to maintain the central device.
8. Require High Maintenance
Since the nodes are connected to the hub, the hub should be maintained all the time in order to transmit the data from the sender to the receiver. Therefore star topology requires more resources and regular maintenance to ensure the hub is working.
9. Low data transfer rates
Usually, the star topology uses wired connections, but when it is impossible to physically connect the nodes, the users can implement wireless star topology. There is a serious concern associated with this star topology.
The wireless star topology cannot handle heavy traffic as this network's data transfer is quite low. The user must use wired connections to work with the heavy load. The slow transmission rate increases the possibility of bottlenecks in the WLAN.
Moreover, if the user wants to set a limit on the network, then the user must perform the settings manually. This means the user will have to spend more time setting up the system. This, in turn, decreases the user's productivity as they have to manage the network along with the project.
Another issue with the wireless star network is that it is relatively difficult to find and resolve the problem in the network. Sometimes the cost of investing in wires is worth more than using a wired network.