Operation Manual

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Appendix B: The Applications Interface CAPI 2.0
English
Appendix B:
The Applications Interface CAPI 2.0
B.1 Introduction
Common ISDN API (CAPI) is a standardized interface
that provides applications with simple access to basic
rate and primary rate ISDN adapters. Applications based
on this standard interface use uniform mechanisms for
communication over ISDN connections, and do not need
to adapt to the peculiarities of different manufacturers’
hardware. Such applications thus become independent
of future extensions or hardware changes. CAPI makes
such modifications transparent to the application. The
ISDN hardware manufacturers benefit from the standard
too, since it makes all kinds of applications compatible
with their products.
Common ISDN API contains an abstract definition of
ISDN services which is not dependent on the specifics of
underlying telecommunications networks or the adapter
cards used to connect computers to ISDN. The
specification provides an interface that is easy for
applications to use, and thus offers uniform access to the
various ISDN services, such as data, voice and fax
transmission, video conferencing and telephony.
Common ISDN API has evolved into an internationally
recognized standard. The key factor in this development
has been the numerous advantages offered by this
uniform interface: independence from specific
manufacturers and resulting high investment security, a
wide variety of compatible applications for all kinds of
operating systems and ISDN protocols, etc. ISDN (the
Integrated Services Digital Network) is becoming attrac-
tive for even more companies, since it affords fast and
reliable transfer of information in many different forms.