|  | 3.3 | How to Identify and Select Networking Capabilities
| 3.3.3 | Three hierarchical WAN design layers
A hierarchical network design includes the following three layers: The core layer provides optimal transport between sites The distribution layer, which provides policy-based connectivity The access layer, which provides workgroup and user access to the network The Figure shows a high-level view of the various aspects of a hierarchical network design.