COMMON-ISDN-API (CAPI) is an application programming interface standard used to access ISDN equipment connected to basic rate interfaces (BRI) and primary rate interfaces (PRI). By adhering to the standard, applications can make use of well defined mechanism for communications over ISDN lines, without being forced to adjust to the idiosyncrasies of hardware vendor implementations. ISDN equipment vendors in turn will benefit from a wealth of applications, ready to run with their equipment.
COMMON-ISDN-API is well established standard. Potential cost savings were the driving force for COMMON-ISDN-API controller and application development. Commercial users are rapidly migrating to ISDN (Integrated Services Digital Network) as the principal vehicle for data exchange of a wide range of formats.