When the network grows above three distribution layers in a single location, a core layer should be considered to optimise the network design.
The core layer is the backbone of the network and aggregation point for multiple networks and distribution layers. It is to provide scalability, high availability and convergence to the network.
The core provides high speed connectivity for large enterprises with multiple campus networks distributed world. It provides interconnectivity between the end user and other network blocks such as the data centre, cloud, WAN, Internet and more.
The core layer r educes the network complexity from (N) x (N – 1) to N links for N distributions.