Module Summary A dial plan is the central part of any telephony solution and defines how calls are routed and interconnected. Dial plan configuration can be complex whether a gateway is used as a Cisco Unified CallManager-controlled H.323 gateway or a Cisco Unified CallManager Express gateway is used. Dial plans in multisite environments require different considerations than dial plans in single-site environments. RSVP can be used to reserve bandwidth between gateways in order to provide CAC. Calling privileges are used within a dial plan to define the destination a user is allowed to call.