A three-tier model of network design is a proven and well-known basic architecture, which is widely used for campus networks. Core-layer switches make up the top layer or core of the network. The aggregation or distribution switches are the intermediary layer . Function: Connection point for all devices on a segment of segment of a network that breaks down and absorbs the data flow between all of the connected devices rather than flooding it to all connected devices. Engineered to aggregate massive volumes of data from distribution switches, it provides ultra-low latency and maximum throughput to ensure uninterrupted routing and packet. The Cisco three-layer hierarchical model provides recommendations for designing campus LANs. Access Layer - Endpoint connectivity and PoE power engineering (IEEE 802. Aggregation Layer - Inter-VLAN routing, policy enforcement, bandwidth. The most common model is the three-tier hierarchy: Access Layer, Distribution Layer, and Core Layer.
