CCNP Quick Reference Sheets Bundle: Exams 642-901, 642-812, 642-845, 642-825

Chapter 1. The Evolving Network Model

Cisco has developed specific architecture recommendations for Campus, Data Center, WAN, branches, and telecommuting. These recommendations add specific ideas about how current technologies and capabilities match the network roles within an enterprise.

Each of these designs builds on a traditional hierarchical design and adds features such as security, Quality of Service (QoS), caching, and convergence.

The Hierarchical Design Model

Cisco has used the three level Hierarchical Design Model for years. This older model provided a high-level idea of how a reliable network might be conceived, but it was largely conceptual because it did not provide specific guidance. Figure 1-1 is a simple drawing of how the three-layer ...