- It is the most common form of network topology .This topology imitates as extended Star topology and inherits properties of bus topology.
- This topology divides the network in to 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 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.
Key Characteristics of this topology are:
- Moderate performance
- if the root goes down, then the entire network suffers even.though it is not the single point of failure.
- Every connection serves as point of failure, failing of which divides the network into unreachable segment.