[This is preliminary documentation and subject to change.]
TAPI version 3.0 basic call controls operate with Windows® 95 or any version of Windows NT® later than 3.5.
Media stream control using the Real-Time Transport Protocol DirectShow™ filters requires Windows NT version 5.0 or later. The DirectShow filters needed are part of Windows NT 5.0 and do not require special installation.
Directory control using Rendezvous for IP Conferencing requires that an ILS server be in place and that the end user has a means of entering the network name of the server.
Two new Telephony Service Providers (TSPs) for IP Telephony and conferences are included with Windows NT 5.0. These can be configured either manually by the end user or programmatically by an application. (See lineAddProvider in the TAPI version 2.1 reference section.)