The scope of the IN distributed functional plane (DFP) architecture for IN capability set 1 (CS-1) is driven by the service requirements of desired CS-1 services, and constrained by the capabilities of the embedded base of evolvable network technology. The scope of functionality required to support desired CS-I services includes functionality to provide: end user access to calYservice processing; service invocation and control; end user interaction with service control; and service management.