Topology is a method / concept used to connect two or more computers, based on the geometric relationship between the basic elements that make up the network, namely nodes, links, and stations.
Network topology selection is based on network scale, cost, destination, and users. The first topology used is the bus topology. each topoology has its own advantages and disadvantages.
Network topology can also make it easier for us to understand how data traffic occurs in a network system. In this way, if we want to make repairs to a network, we no longer need to be confused about where to start fixing it from. Because this network topology has clearly described how the network system is formed.
Types of Topology on Computer Networks
1. Bus Topology
This topology is the earliest topology used to connect computers. The transmission medium used in this topology uses only one long cable equipped with several terminals, and at the end of the cable must be terminated by one terminator. The coaxial cable is the transmission medium in this topology. Even though it looks simple, the bus topology is rarely used in building network systems. This may be due to several shortcomings, including the possibility of data flow collisions, and also if an error occurs on one of the devices, the network will immediately go down.
Advantages and disadvantages (Bus Topology)
- Network development or adding new workstations can be done easily without disturbing other workstations.
- If one computer fails the network, the other networks are not affected and they continue to work. The bus network is easy to set up and very simple.
- The bus network uses very few cables (saves cables, is cost effective) and is very simple.
- Simple cable layout.
- Implementation does not require large costs compared to other network topologies.
- Bila ada gangguan di sepanjang kabel pusat maka seluruh jaringan juga akan mengalami gangguan.
- Dalam jaringan bus dibutuhkan sambungan jaringan untuk menentukan data transfer antara dua node.
- Jika laju transfer data terlalu tinggi maka jaringan Bus tidak dapat bekerja dengan baik karena data pada stream tidak boleh kelebihan beban
- Jaringan bus kurang cocok sebagai jaringan yang besar karena terdapat keterbatasan jumlah node yang dapat diatur untuk satu kabel.
- Diperlukan Repeater untuk jarak jauh.
- Agak sulit dalam memecahkan masalah.
- Jika kebutuhan jumlah komputer meningkatkan dalam jaringan, laju transfer data akan terasa sangat menurun.
2. Ring Topologi
As the name implies, in this topology each computer is arranged in the form of a ring or ring. A data token given to give permission for each computer to communicate. Where each knot arranged communicates in a circular formation to form a ring. In other words, each computer is connected to each other between two other computers.
Advantages and disadvantages (Ring Topology)
- The installation cost is quite cheap (Save cables)
- Low installation complexity (Easy to design and install)
- Has better performance than Bus network topology.
- Easy to reconfigure and install new devices.
- A relatively simple data transmission such as a packet traveling in one direction only.
- There will be no collision data delivery (collision), because at one time only one node can transmit data.
- It is easy to track and isolate errors in the network because it uses a point to point configuration
- Network error sensitive, so that if there is a problem at a node it will disrupt the entire network. but this can be anticipated by using a dual ring ring.
- Difficult for network development, because adding, changing and moving network devices will affect the entire network.
- More difficult to configure than Star topology
- Communication performance in the network is very dependent on the number of nodes / points on the network.
- It requires special management and handling of bandles
- Troubleshooting is arguably quite complicated.
- The data packet has to pass through each computer between the sender and receiver because this makes it slower.
3. Star Topology
In this topology, each computer is connected to each other in such a way as to form a star, where each device is connected around the hub / switch as the consentrator. This topology is most often used in LAN (local area network) networks. This topology is often used in homes, offices, schools, computer labs, and so on. all computers connected to the star topology require a hub, switch, or router with the transmission medium a UTP / STP cable.
Advantages and disadvantages (Star Topology)
- The management and installation of this star-shaped network is very easy and simple in terms of functionality
- Damage to one channel only affects the network on that channel (which is damaged) and stations that are linked.
- Ease of detection and isolation of network management errors / damage.
- The level of security is high.
- Centralized access control.
- It is very easy to solve problems, because all types of computer networks are always dependent on a central hub, meaning that every problem in the operation of the network being operated on can be traced to the central hub.
- Addition or subtraction of stations can be done easily.
- Data packets do not have to make their way through various nodes which will ensure fast data transfer.
- Every problem in one node will not interfere with the performance of other nodes in a network.
- Replacing and adding new machines is very easy in Star topology, and does not interfere with the network to other nodes.
- Resistant to busy network traffic.
- Network costs are more expensive than Ring and Bus.
- Very dependent on the function of the central hub.
- Requires more cables than a bus topology, which results in a rather high cost of manufacture.
- The size of this network depends on how many connections can be made to the hub.
- If one of the many nodes makes use of a significant portion of the processing capability of the central hub, it will affect the performance of other nodes.
- The performance of the entire network is directly dependent on the performance of the hub. If the server is slow, it will cause the entire network to slow down.
- Wasteful in cable use.
- If the middle node is damaged, then the whole series will stop.
- HUB / SWITCH is a critical element because of centralized control.
- The network depends on the central terminal.
- The role of the hub is very sensitive so that when there is a problem with the hub, the network will go down.
- If you use a HUB and heavy data traffic can cause slow network.
4. Mesh Topology
In this topology, every computer is connected to one another. In other words, each computer can directly communicate with other computers. As a result, to apply this topology, each computer must have many interfaces in order to be connected to other computers.
Advantages and disadvantages (Mesh Topology)
- Mesh topology is a strong network because when one link in the mesh network topology becomes unstable it will not cause the whole system to stop.
- It is Robust in nature, that is, if there is a disturbance on the connection of a computer, for example computer A and computer B due to damaged connection cables (links) between computers B and A, the interference will not affect the connection between computer A and other computers.
- Special links are used to ensure that each connection is capable of carrying the data load, eliminating common data traffic problems when multiple devices are sharing.
- If there is network expansion, it will not cause interference to other network users.
- This topology ensures the confidentiality and security of data, because each message travels along a special link.
- Data transmission, from one node to a number of other nodes can be done simultaneously
- Requires a lot of I / O (Input-Output) ports and cables. the more computers, the more I / O ports and cable links are needed
- The cost of installing and maintaining a mesh computer network is quite high.
- The main weakness of the mesh topology is that it requires more network hardware (ex: network cables) compared to other LAN network topologies
- The implementation (configuration and installation) of this topology is quite complicated.
- Need a large space because it uses a lot of cables.
5. Tree Topology
This topology can also be called a combination of a star topology and a bus topology. This topology is also commonly referred to as a multilevel topology, and is very suitable for application in multilevel offices. This Type Tree computer network topology is ideal for use on computer network systems. In a tree network, there are several levels of nodes or nodes. The center or vertex of a higher level, can control the knots below the level. This topology combination supports future upgrades of computer networks, much better than the bus or star.
Advantages and disadvantages (Tree Topology)
- It is a good topology for large computer networks compared to other types of computer topologies such as star and ring which are not suitable for scaling the entire network. The tree topology divides the entire network into manageable sections.
- All computers in the tree topology have immediate access to neighboring nodes in the network as well as a central hub. A tree network allows multiple network devices to be connected by a central hub.
- The tree topology makes it possible to have a point to point network.
- The tree topology provides sufficient space for future network expansion
- Overcoming the limitations of the star network topology, which has shortcomings at the hub connection points and the limitations of broadcast traffic induced by the bus network topology.
- Uses a lot of cables
- If an error occurs on the high-level (central) network / computer, then the low-level network will be interrupted as well.
- Collisions often occur and the performance is relatively slow
- The dependence of the entire network on one central hub is a vulnerability point for this topology. Central hub failure or main data cable trunk failure, can cripple the entire network.
- With the increase in size beyond the point, management becomes difficult.
6. Hybrid Topology
Hybrid Topology – Hybrid topology is a combination of two or more different topologies and blends into one new form of a computer network system. If different topologies are connected to each other and do not show one particular topology characteristic, then the topology can be said to be a hybrid network topology.
Advantages and disadvantages (Hybrid Topology)
- Hybrid topology combines different configurations but can work perfectly for different amounts of network traffic.
- One of the prominent advantages of the hybrid topology is its flexibility. The hybrid network topology is designed in such a way that it can be applied to a number of different network environments.
- Adding other peripheral connections is fairly straightforward, such as new nodes.
- When a certain link in a computer network is interrupted, it does not hinder the work of other networks.
- Topology speed is classified as consistent, such as combining the advantages of each topology and eliminating the drawbacks.
- Can be combined with various other computer network topologies without the need to make any changes to the existing topology.
- Because it is a combination of several topological forms, topology management will be more difficult.
- Configuration and installation of this topology is difficult because there are different topologies that must be connected to one another, at the same time it must be ensured that none of the network nodes fail to function, making configuration and installation in the hybrid topology complicated.
- From an economical point of view, hybrid networks are difficult to maintain because they require higher costs compared to pure network topologies or in one form. This cost factor is related to the cost of adding hubs and increasing wiring costs.