Types of Network Topologies - GeeksforGeeks (2023)

The arrangement of a network of nodes and connecting lines through transmitters and receivers is referred to as a network topology. The different network topologies are:

Mesh-Topologie:

In a mesh topology, each device is connected to another device via a specific channel. In the mesh topology, the protocols used are AHCP (Ad Hoc Configuration Protocols), DHCP (Dynamic Host Configuration Protocol), etc.

illustration 1: Each device is connected to another via dedicated channels. These channels are called links.

• Assuming N devices are connected in a mesh topology, the total number of ports each device requires is N-1. In Figure 1, 5 devices are connected together, so the total number of ports required for each device is 4. The total number of ports required = N*(N-1).
• Assuming N devices are connected in a mesh topology, then the total number of dedicated links needed to connect them is equal^NorteC₂that is, N(N-1)/2. In Figure 1, 5 devices are connected together, so the total number of links needed is 5*4/2 = 10.

Advantages of this topology:

• Communication between the nodes is very fast.
• it is sturdy
• The error is easy to diagnose. Data is reliable because data is transmitted between devices over dedicated channels or links.
• Provides security and privacy.

Problems with this topology:

• Installation and configuration are difficult.
• The cable cost is high as it requires bulk wiring, making it suitable for fewer devices.
• The maintenance effort is high.

Star topology:

In the star topology, all devices are connected to a single hub via a cable. This hub is the central node and all other nodes are connected to the central node. The hub can be passive in nature, i. H. it is not an intelligent hub like streaming devices, at the same time, the hub can be called an active hub. Active hubs contain repeaters. Coaxial cables or RJ-45 cables are used to connect the computers. Many common Ethernet LAN protocols are used in the star topology, such as B. CD (Collision Detection), CSMA (Carrier Sense Multiple Access), etc.

Figure 2– A star topology where four systems are connected with a single connection point, i. H. a hub.

Advantages of this topology:

• When N devices are connected in a star topology, the number of cables needed to connect them is N. Therefore, it is easy to configure.
• Each device only needs 1 port i.e. to connect to the hub, so the total number of ports needed is N.
• it is robust. If a link fails, only that link is affected and no other links are affected.
• Easy fault identification and isolation.
• The star topology is inexpensive because it uses inexpensive coaxial cable.

Problems with this topology:

• If the hub on which the entire topology is based fails, the entire system collapses.
• Installation costs are high.
• The performance refers to the single hub, i.e. the hub.

Bus-Topology:

Bus topology is a type of network in which each computer and network device is connected with a single cable. It's bi-directional. It's a multipoint connection and a non-resilient topology because if the backbone fails, the topology crashes. In the bus topology, various MAC (Media Access Control) protocols are followed by Ethernet LAN connections such as TDMA, Pure Aloha, CDMA, Slotted Aloha, etc.

Figure 3: A bus topology with shared backbone cable. The nodes are connected to the channel via stubs.

Advantages of this topology:

• If N devices are connected together in a bus topology, then the number of cables needed to connect them is 1, known as trunk cables, and N spurs are required.
• Coaxial or twisted pair cables are mostly used in bus-based networks that support up to 10 Mbit/s.
• Cable costs are lower compared to other topologies, but used to build small networks.
• The bus topology is a familiar technology as installation and troubleshooting techniques are well known.

Problems with this topology:

• A bus topology is much simpler, but still requires a lot of cables.
• If the red thread fails, the entire system collapses.
• When network traffic is heavy, it increases network collisions. To avoid this, several well-known protocols such as Pure Aloha, Slotted Aloha, CSMA/CD, etc. are used on the MAC layer.
• Adding new devices to the network would slow down networks.
• Security is very low.

Ringtopologie:

In this topology, it forms a ring that connects devices to exactly two neighboring devices.

Multiple repeaters are used for ring topologies with a large number of nodes, because if someone wants to send data to the last node of a 100-node ring topology, the data has to traverse 99 nodes to reach 100 nodes. In order to avoid data loss, repeaters are used in the network.

Data only flows in one direction, i. H. they are unidirectional, but they can be bidirectional and have two connections between each network node, which is called a dual ring topology. Ring topology, workstations use the Token Ring Passing protocol to transfer data.

Figure 4: A ring topology consists of 4 stations that are connected to form a ring.

The most common access method in the ring topology is token passing.

• Step-Token:It is a network access method in which a token is passed from one node to another node.
• Symbolic:It's an act that circulates through the network.

The following operations that take place in the ring topology are:

1. A station is denoted asMonitorStation taking full responsibility for conducting operations.
2. In order to transmit the data, the station must have the token. After the transmission is complete, the token is released for use by other stations.
3. When no stations are transmitting data, the token circulates on the ring.
4. There are two types of token release techniques:Early token releaseRelease the token right after the data is transferred anddelayed token releasereleases the token after receiving confirmation from the recipient.

Advantages of this topology:

• The data transfer takes place at high speed.
• The possibility of a collision is minimal with this type of topology.
• Inexpensive to install and expand.
• It's cheaper than a star topology.

Problems with this topology:

• The failure of a single node in the network can lead to the failure of the entire network.
• Troubleshooting is difficult in this topology.
• Adding intermediate stations or removing stations can disrupt the overall topology.
• Less sure.

Baumtopologie:

This topology is a variant of the star topology. This topology has a hierarchical data flow. Protocols such as DHCP and SAC (Standard Automatic Configuration) are used in the tree topology.

Figure 5: In it, the various secondary hubs are connected to the central hub that contains the repeater. This data flows from top to bottom, i. H. from the central hub to the secondary hub and then to the devices, or from the bottom up, i. H. from the devices to the secondary hub and then to the central hub. It is a multipoint connection and not robust. Topology, because if the backbone fails, the topology fails too.

Advantages of this topology:

• Allows more devices to be connected to a single central hub, reducing the distance a signal travels to reach devices.
• It allows for network isolation and prioritization of different computers.
• we can addnew devices to the existing network.
• error detectionjcorrection errorare very simple in a tree topology.

Problems with this topology:

• If the central hub fails, the entire system fails.
• The cost is high because of the wiring.
• As new devices are added, it becomes difficult to reconfigure them.

Hybridtopologie:

This topological technology is the combination of all the different types of topologies that we have previously explored. It is used when nodes can take any shape. This means that they can be single topologies such as ring or star, or a combination of the different topology types shown above. Each individual topology uses the protocol discussed above.

Figure 6: The figure above shows the structure of the hybrid topology. As you can see, it contains a combination of all different types of networks.

Advantages of this topology:

• This topology isvery flexible.
• The network size can be easily expandedAdding new devices.

Problems with this topology:

• It is a challengeto design the architectureof the hybrid network.
• hubsused in this topologyvery expensive.
• The infrastructure costs are too high as a hybrid networkrequires lots of cables and network equipment.