FXS and FXO Supervisory Signaling

FXS and FXO Supervisory Signaling
FXS and FXO interfaces indicate on-hook or off-hook status and the seizure of telephone
lines by one of two access signaling methods: loop-start or ground-start. The type of
access signaling is determined by the type of service from the telephone company’s CO.
Standard home telephone lines use loop-start, but business telephones can order groundstart
lines instead.