Supporting ISDN−TA Modems
There are two common types of Integrated Services Digital Network Terminal Adapters (ISDN−TAs):
Parallel bus (for example, ISA and PCI) devices that are driven by NDIS WAN drivers.
Serial port devices that are supported by Unimodem.
This topic addresses how to support the second type, serial port ISDN adapters, referred to herein as either ISDN-TAs or ISDN modems.
ISDN modems share common features:
ISDN Basic Rate Interface (2B + D)
Serial AT command language, with proprietary ISDN extensions
This topic describes registry entries that support both the static and dynamic configuration of ISDN modems in Windows 2000 and later versions of the operating system. Specifically, this topic describes the proprietary and standard (V.254) commands that configure and control ISDN modems under Unimodem. For more information about the static and dynamic configuration of ISDN modems, see Static Configuration and Dynamic Configuration.
ISDN-related entries are preceded by the string, HKR, ISDN\, which places them in the appropriate registry subfolder. There is no entry for ISDN modems equivalent to the Properties entry for PSTN (analog) modems. ISDN modem properties are set through separate INF file entries. The presence of the ISDN-related entries in the INF file activates the associated portions of the user interface and identifies the protocols that the ISDN modem supports for TAPI.