Extended Telephony Phone Functions

The Extended phone services (or Device-Specific phone services) include all extensions to the TAPI defined by the service provider. TAPI defines a mechanism that enables service-provider vendors to extend TAPI using device-specific extensions. TAPI defines only the extension mechanism, and by doing so provides access to device-specific extensions. TAPI does not define their behavior, which is completely defined by the service provider.

TAPI consists of scalar and bit-flag data constant definitions, data structures, functions, and messages. Procedures are defined that enable a vendor to extend most of these, as described in the following topics.

• Scalar Data Constants
• Bit-Flag Data Constants
• Functions and Messages