Modern Three-Layer Hierarchical Network Architecture
Having understood networking topologies, routers and switches, and so on, we take a quick look at Fig. 1.2, which represents a typical, modern three-layer Ethernet network architecture, mainly popularized by Cisco. It also includes a connection to the Internet. The basic purposes of the three layers can be summarized as follows.
FIGURE 1.2 Hierarchical three-layer network architecture (and where PoE fits in).
This is the high-speed “backbone” of the “inter-network.” The core ...