Network topology is the arrangement of the various elements (links, nodes, etc.) of a computer network. Essentially, it is the topological structure of a network and may be depicted physically or logically.
Network topologies are categorized into the following basic types:
Point-to-point (PTP) topology connects two nodes directly together using a single piece of cable. The example of pure point to point links is two computers communicating via modems.
2) Bus Topology:
Bus topology is the cheapest way of connecting computers used by small organization in which device are connected to a single cable. In Bus Topology, each node is directly connected to a cable.
- Bus Topology is less expensive.
- It is easy to use and understand.
- It's easy to connect a computer or device.
- It is easy to extend a network.
- In a heavy network, it becomes slow.
- The entire network shuts down if there is a break in the main cable.
3) Star Topology:
In a star network all nodes are connected to a device, which may be a hub, a router or a switch. This central device is acting as a server and other nodes are as clients. Every communication is pass through this central device. In star network, devices typically connect to the hub with Unshielded Twisted Pair (UTP).
- Unlike Bus Network, the failure of a single node or cable doesn't affect the entire network.
- Easy to add another workstation to the network.
- By using centralized networking device, it reduces cost.
- Failure of the central device will causes the whole network failure.
4) Ring Topology:
In ring topology, each node is connected to exactly two other nodes, creating a circular network structure. Each packet is sent in one direction on a ring until it reaches its final destination.
- It eliminates the cost of using central host.
- It continue to function after capacity is exceeded but the speed will be slow.
- Failure of any node in the network, can affect the whole network.
- To add or remove any node will disrupts the network.
5) Mesh Topology:
A mesh network uses a network topology in which each node (called a mesh node) relays data for the network. In this type, a host is connected to one or two or more than two hosts. All nodes cooperate in the distribution of data in the network.
- Main advantage of mesh topology is fault tolerance, mean if there is any cable breaks then traffic can be routed through different path.
- As it uses multiple pathways, if required additional cabling and network interfaces.
- It is very hard to manage.
6) Tree Topology:
It is also known as Hierarchical Topology. A tree topology is essentially a combination of bus topology and star topology. This topology divides the network in to multiple levels/layers of network
It has a root node, intermediate nodes, and ultimate nodes. This structure is arranged in a hierarchical form and any intermediate node can have any number of the child nodes.
An example of this network could be cable TV technology. Other examples are in dynamic tree based wireless networks for military, mining and otherwise mobile applications.
- It is scalable. Secondary nodes allow more devices to be connected to a central node.
- Point to point connection of devices.
- Having different levels of the network makes it more manageable hence easier fault identification and isolation.
- Maintenance of the network may be an issue when the network spans a great area.
- Since it is a variation of bus topology, if the backbone fails, the entire network is crippled.
7) Hybrid Topology:
Hybrid topology is the interconnection of two or more basic topologies, each of which is laid out so the resulting network does not display a standard topology. Internet is the best example of largest Hybrid topology.