ITBasicCallControl::Connect() returns TAPI_E_OPERATIONFAILED when using a UMDF-ComPort-Driver RRS feed

  • Question

  • Is it possible to use TAPI on top of a UMDF-ComPort-Driver?

    I wrote a UMDF-Driver, based on the VirtualSerial Sample Driver.

    I install it using DeviceManager. It gets attached to COM7.

    I install a "Modem" on COM7 using the "Phone and Modem Options" in the ControlPanel. My modem-driver-package has just an INF-file, which I copied from an installation of a real modem.

    When I install my modem-driver-package on a real COM-port ITBasicCallControl::Connect() returns 0 (S_OK) on this port.

    When I install my modem-driver-package on COM7 (on top of my virtual COM-port), ITBasicCallControl::Connect() returns TAPI_E_OPERATIONFAILED .

    My virtual Driver replies to all the IO-Control-requests it gets in exactly the same manner as the COM-port attached to the real Modem. But it never gets an ATD-command. Why?

    Monday, December 9, 2013 12:02 PM