PSTN switching

To assure that the PSTN switching  equipment has sufficient time to restore to the idle condition, the system will hold analog CO lines in a busy state to  users  after release  of a CO line  by a station.   The time between the station disconnect and  when the system changes the  CO line status  from busy to idle is the CO Line Release Guard time. Operation System Operation of this feature  is automatic. Conditions Programming  SYSTEM Related Features