There are various basic types of network topologies, which differ in the arrangement of devices and have various advantages and disadvantages. The most common topologies are:
Star topology
Concept: In a star topology, all nodes (computers, printers, etc.) are connected to a central hub or switch. Each node has its own connection to this central device.
Advantages: Easy to set up and manage. Adding or removing devices is simple and does not affect the rest of the network. Fault detection is easier as each device is connected to a central hub.
Disadvantages: The central hub is a single point of failure. If it fails, the entire network can be affected.
Example: A home Wi-Fi network in which several devices such as laptops, smartphones and smart TVs are wirelessly connected to a central router.
Bus topology
Concept: In the bus topology, all nodes are connected with a single backbone cable. The data sent from a node is transmitted in both directions until it reaches its destination node.
Advantages: Requires less cable length than other topologies and is easy to implement for small networks.
Disadvantages: Limited in size and scope. The entire network can become inoperable if the backbone cable fails or if too many devices are connected, resulting in signal degradation.
Example: Old Ethernet networks often used a bus topology where the computers were connected with a thin coaxial cable with BNC connectors.
Ring topology
Concept: The nodes in a ring topology are connected to each other in a circle. Each node is connected to two other nodes and forms a ring. The data moves in one direction and is forwarded from one node to another until it reaches its destination.
Advantages: As the data is transmitted in one direction, there are no data collisions. It is also relatively easy to recognize and isolate errors.
Disadvantages: The failure of a single node or connection can disrupt the entire network, unless it is a dual ring or bypass technology.
Example: Some old classroom computer labs may have used a ring topology for networked computers, where each computer was connected to its neighboring counterpart.
Tree topology
Concept: Starting from a root node, this hierarchical structure branches out through various levels of sub-nodes. The topology combines elements of star and bus topology. Star-shaped groups of devices are connected by a backbone.
Advantages: The simple expansion by adding branches and levels to the network enables high scalability. As all information runs via the central node, errors can be easily identified.
Disadvantages: Failure of the backbone cable can bring the entire network to a standstill. The topology is also susceptible to attacks, as compromised devices can potentially access all data.
Examples: Examples of the use of tree topology can be found in computer networks, especially in home or small office environments where multiple devices such as printers and computers need to be connected, often creating bus networks around a main server.
Mesh topology
Concept: Each node in a mesh topology is connected to every other node. There are potentially two types of mesh topologies: Full Mesh, where every node is connected to every other node, and Partial Mesh, where nodes are selectively connected to each other.
Advantages: Provides high reliability and redundancy. If a node fails, alternative paths can be used for data transmission.
Disadvantages: Complex configuration and management due to the large number of connections. It is also expensive due to the large number of cables and connections required.
Example: The Internet itself can be seen as an example of a mesh topology, with multiple paths between any two nodes in the network.
Hybrid topology
Concept: a hybrid topology is a combination of two or more different topology types. For example, a large office building could use a star topology for each floor but connect the floors together using a ring topology.
Advantages: Extremely flexible, as components of different topologies can be integrated to best suit the requirements at hand.
Disadvantages: The design can be complex and costly, depending on which topologies are combined.
Example: A company network in which the individual departments are organized in a star topology, while the departmental networks for communication between the departments are connected in a ring or bus.
