4Abbreviations and Terminology OpenPhone IPC
Abbreviations and Terminology
AEC (Acoustic Echo Cancellation):
Filter out those frequencies emitted
by the loudspeaker that would be
picked up by the microphone. Pre-
vents the call-partner at the other
end from receiving their own echo.
Codecs:
Compression (and decompression)
of audio data, in real time, before
transportation via the Internet Pro-
tocol thus reducing network load.
DirectSound:
Application programming interface
developed by Microsoft for control-
ling the sound card. Makes is possi-
ble to simultaneously output the au-
dio data of multiple applications.
Using Microsoft Windows XP, AEC is
also supported.
Dynamic Jitter Buffer
Adjustment:
Smooths out delays, caused by dif-
fering network utilisation, that can
occur during transportation of real-
time audio data via the Internet Pro-
tocol.
Echo suppression:
While a call-partner is talking, the
microphone is suppressed. Reduces
the voice echo for the call-partner.
RAS (Remote Access Server):
Makes the creation of a network
connection via Modem, ISDN or DSL
possible.
RTP / RTCP (Real Time Protocol /
Real Time Control Protocol):
Protocols for the transportation of
real-time audio data via the Internet
Protocol.
Skin:
Interchangeable graphical user in-
terface.
TAPI (Telephony Application
Programming Interface):
A from Microsoft and Intel devel-
oped programming interface for te-
lephony applications using Microsoft
Windows.
TSP (TAPI Service Provider):
Hardware dependent driver module
to provide TAPI functionality for spe-
cific devices (e.g. for the
OpenCom 100).
VAD (Voice Activity Detection):
Recognition of speech pauses that,
to reduce network load, are not sent.
