Dial plans are essential for any Cisco Unified Communications deployment. Whether implementing single-site or multisite deployments, having a thorough understanding of dial plans and the knowledge of how to implement them on Cisco gateways is essential for any voice implementation engineer. This chapter describes the characteristics of both dial plans and numbering plans.
A dial plan is the central part of any telephony solution and defines how calls are routed and interconnected. A dial plan consists of various components that can be used in many combinations. This section describes the components of a dial plan and how they are used on Cisco IOS gateways.