2.1 Overview

This chapter provides an overview of the Telephony Service Provider Interface. It describes how Telephony Service Providers fit into the Windows Telephony service in particular and the Windows environment in general. This includes information regarding the relationship between the Telephony Application Programming Interface (TAPI) and the Telephony Service Provider Interface (TSPI). The chapter also describes basic concepts including the relationships between functions, messages, data types, and the "life cycle" model that determines the sequence in which these are used.