Nortel Circuit Card Installation Manual page 599

Figure 134
Two-way, loop OAID, TIE trunk call states – incoming call from far-end PBX
Ground on tip,
battery on ring
Idle
Forced
near end
disconnects
Far end
disconnect
Battery-ground
or loop pulses,
or DTMF
Far end
originates
NT8D14 Universal Trunk card
System (near) end
Battery on tip,
ground on ring
Near end
disconnects
first
Circuit Card
Page 599 of 906
Far end
disconnects
first
Near end
answers
553-AAA1145
Description and Installation