What is Network Topology ?
Network topology refers to the physical or logical layout of a network. It defines the way different nodes are placed and interconnected with each other. Alternately, network topology may describe how the data is transferred between these nodes.
Types of Network Topology:
- Bus Topology
- Star Topology
- Ring Topology
- Mesh Topology
- Tree Topology
- Hybrid Topology
Bus topology is a network type in which every computer and network device is connected to single cable. When it has exactly two endpoints, then it is called Linear Bus topology.
Advantages of Bus Topology
- It is easy to set-up and extend bus network.
- Cable length required for this topology is the least compared to other networks.
- Bus topology costs very less.
- Linear Bus network is mostly used in small networks. Good for LAN.
Disadvantages of Bus Topology
- Cables fail then whole network fail.
- If network traffic is heavy or nodes are more the performance of the network decreases.
- Cable has a limited length.
- It is slower than the ring topology.
in Star topology All hosts are connected to a central device, known as hub device, using a point-to-point connection. That is, there exists a point to point connection between hosts and hub.
Advantages of Star Topology:
- Fast performance with few nodes and low network traffic.
- Hub can be upgraded easily.
- Easy to troubleshoot.
- Easy to setup and modify.
- Only that node is affected which has failed, rest of the nodes can work smoothly.
Disadvantages of Star Topology
- Cost of installation is high.
- Expensive to use.
- If the hub fails then the whole network is stopped because all the nodes depend on the hub.
- Performance is based on the hub that is it depends on its capacity
It is called ring topology because it forms a ring as each computer is connected to another computer, with the last one connected to the first. Exactly two neighbours for each device.
Advantages of Ring Topology
- Transmitting network is not affected by high traffic or by adding more nodes, as only the nodes having tokens can transmit data.
- Cheap to install and expand
Disadvantages of Ring Topology
- Troubleshooting is difficult in ring topology.
- Adding or deleting the computers disturbs the network activity.
- Failure of one computer disturbs the whole network.
This topology divides the network into multiple levels/layers of network. Mainly in LANs, a network is bifurcated into three types of network devices. The lowermost is access-layer where computers are attached. The middle layer is known as distribution layer, which works as a mediator between upper layer and lower layer. The highest layer is known as core layer and is central point of the network, i.e. root of the tree from which all nodes fork.
Advantages of Tree Topology
- Extension of bus and star topologies.
- Expansion of nodes is possible and easy.
- Easily managed and maintained.
- Error detection is easily done.
Disadvantages of Tree Topology
- Heavily cabled.
- If more nodes are added maintenance is difficult.
- Central hub fails, network fails.
It is a point-to-point connection to other nodes or devices. All the network nodes are connected to each other. Hosts in Mesh topology also work as a relay for other hosts which do not have direct point-to-point links.
Mesh technology havs two types:
- Partial Mesh Topology : In this topology some of the systems are connected in the same fashion as mesh topology but some devices are only connected to two or three devices.
- Full Mesh Topology : Each and every nodes or devices are connected to each other.
Advantages of Mesh Topology
- Each connection can carry its own data load.
- It is robust.
- Fault is diagnosed easily.
- Provides security and privacy.
Disadvantages of Mesh Topology
- Installation and configuration are difficult.
- Cabling cost is more.
- Bulk wiring is required.
It is two different types of topologies which is a mixture of two or more topologies. For example, if in an office in one department ring topology is used and in another star topology is used, connecting these topologies will result in Hybrid Topology (ring topology and star topology).
Advantages of Hybrid Topology
- Reliable as Error detecting and trouble shooting is easy.
- Scalable as size can be increased easily.
Disadvantages of Hybrid Topology
- Complex in design.