A typical campus network consists of the terminal layer, access layer, aggregation layer, core layer,...

In the latest Huawei Xinghe Intelligent Campus (V2.0) architecture, the network is officially categorized into a four-layer architecture : Terminal Layer , Network Layer (which includes Access, Aggregation, and Core), Management Layer (iMaster NCE), and Application Layer . While the components mentioned (Egress, O & M) are physical zones, the "Typical Architecture" definition in HCSP documentation distinguishes between the layers of the infrastructure and the functional zones . Furthermore, in many modern SDN-based designs (like the Xinghe solution), the aggregation layer is often optional or collapsed, and the "O & M zone" is formally referred to as the Management and Analytics Layer .