Extended Phone Services

The Extended Phone Services (or device-specific phone services) include all extensions to TSPI defined by the service-provider. TSPI defines a mechanism that enables service-provider vendors to extend TSPI using device-specific extensions. TSPI only defines the extension mechanism, and by doing so provides access to device-specific extensions, whose behavior is completely defined by the service provider.

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