V-Tap ISDN BRI Manual EN v2.6 Dec 2018 © 2017-2018 Vidicode 22
3.3.9
ISDN settings
Stereo Recording (else Mono)
An ISDN line gives the possibility to record the local and remote sides
of a call separately. The V-Tap ISDN can combine the two sides in a
stereo WAV file. The only drawback is, that the files will be twice as
big, because 16000 bytes per second must be stored then, instead of
8000 bytes per second for the Mono/Mixed mode.
Audio is u-Law (else A-Law)
Some countries, such as the USA and some in Asia, use a different
type of codec to transport the audio. This is most of the time
combined with 56 Kbps data rate (see below).
When the G.711 u-Law codec is not used, the standard G.711 A-Law
is taken. A-Law is used in all European countries.
Rate is 56 Kbps (else 64 Kbps)
Some countries, such as the USA and some in Asia, have a different
type of data rate on the ISDN lines. In all European countries, the
data rate is 64 Kbps.
Reversed D-channel Operation
It might be that the Rx and Tx wires in the cable are reversed. In that
case, the V-Tap ISDN will still record all calls correctly, except that
inbound and outbound are reversed.
In other words, when the local and remote phone numbers are
reversed in the database software, this parameter must be enabled.
