Nortel Networks 4430 Network Card User Manual


 
Analog Voice ModulesPassport 4400 Hardware Installation Manual
6-2
Signaling Formats
Use the information and figures below to ensure you are using the correct
interfaces in your Analog Voice Modules.
FXS
Provides ringing voltage and battery to the attached telephone
equipment.
Selected when the voice channel is connected directly to a telephone
instrument, to the trunk side of a key telephone system, or to the central
office trunk of a Private Branch Exchange (PBX).
Must never be connected to a telephone interface that also provides
ringing voltage, such as Central Office equipment, a PBX station, or off-
premise circuit.
Figure 6-2. Interface Requirements for FXS
FXO
Normally attaches to the station side of a PBX or Central Office loop
start equipment.
Accepts ringing voltage from the attached Central Office line of PBX but
does not provide ringing voltage or battery.
Figure 6-3. Interface Requirements for FXO
Voice Channel
FXS
Key
Telephone
System
PBX
Trunk Side
Station Side
When the Telephone Interface is:
Use
FXO
C
PBX
Voice Channel
Trunk Side
Analog
Station Side
When the Telephone Interface is:
Use