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SPA400 Field Reference
Setup
SPA9000 Voice System Administration Guide 266
C
Line Settings
Transmit Gain The gain level that the SPA400 may use to increase or
attenuate the power level before transmitting to the
telephony port
NOTE Change this setting if remote call participants have
trouble hearing the users of the SPA9000 Voice System. Make
changes in increments of 3 dB; changes of less than 3 dB will
not have a perceptible impact.
Default: 0
Receive Gain The gain level that the SPA400 may use to increase or
attenuate the power level before receiving on the telephony
port
NOTE The default Receive Gain settings should be
satisfactory in most use cases. Unnecessary changes in
Receive Gain can cause problems with echo.
Default: 0
Impedance The impedance of the lines that are connected to SPA400’s
telephony ports
Default: 600 Ohms
Tip/Ring voltage The tip-to-ring voltage reserved for voice transmission
Default: 3.5 Volts
Operational loop
current Min
The minimum loop current that maintains an off-hook state. If
the loop current drops below this value, the phone enters on
hook state.
Default: 10 mA
On-Hook speed The time that the loop current drops to 0mA when the phone
enters the on-hook state.
Default: Less than 0.5ms
Ring frequency Min The minimum frequency of a valid ring
Default: 10
Ring frequency Max The maximum frequency of a valid ring
Default: 100
Ring Validation Time The minimum duration of a valid ring
Default: 256ms