CALL PROCESSING SERVER AND PROVIDED SERVICE TRANSITION METHOD IN CALL PROCESSING SERVER

PROBLEM TO BE SOLVED: To provide a call processing server which makes it possible to start a new telephone service with the user's desired timing and execute a transition process without leaving a period in which services would otherwise be interrupted during a transition to the new telephone service, and a method for changing over provided services in the call processing server.SOLUTION: The call processing server comprises: a transition state recording unit 12 which records transition state information indicating the current state of whether before or after transition to a new service separately for each of user terminals 20; a transition determination unit 16 which, by analyzing an incoming signal from a user terminal 20 as the subject of transition, determines whether or not the user is the one who uses a post-transition service; a transition state reference and update unit 14 which, when the user is found to be the one who uses a post-transition service, updates the transition state information recorded in the transition state recording unit 12 from "pre-transition" to "post-transition"; and a service processing unit 15 which changes telephone service contents on the basis of the transition state information recorded in the transition state recording unit 12 before providing the user terminal 20 with telephone services.