ADTRAN ISU 512 User Manual
Page 44
Chapter 5: Configuration
28
ISU 512 User Manual
61202.086L1-1
Speech
Speech directs the call control software to request a Mu-law/A-law speech cir-
cuit as the bearer capability for outgoing calls. The Speech option is used with
an ISDN line configured for voice service. In some areas voice service costs
less than data service. A Speech call type does not guarantee an end-to-end
digital connection with some local and long distance carriers.
Audio
Audio directs the call control software to request a 3.1 kHz audio circuit as the
bearer capability for outgoing calls. The Audio option is used with an ISDN
line configured for voice service. In some areas audio service is less expensive
than data service. Selecting an Audio call type guarantees a digital end-to-end
ISDN connection.
Data 56 kbps
Data 56 kbps directs the call control software to request a 64 kbps data circuit
that is rate-adapted to 56 kbps. Data 56 kbps is intended for use in circum-
stances where interoperability with Switched 56 service is desired.
Data 64 kbps (default)
The default Call type for ISDN service is Data 64 kbps. This directs the call
control software to request an unrestricted 64 kbps circuit.