Nortel Circuit Card Installation Manual page 601

Figure 136
Two-way, loop OAID, TIE trunk call states – outgoing call to far-end PBX
System (near) end
Ground on tip,
battery on ring
Idle
Near end
disconnect
Far end
disconnect
Near end
disconnects
first
NT8D14 Universal Trunk card
Battery on tip,
ground on ring
Far end
disconnects
first
Circuit Card
Page 601 of 906
Near end
originates
Far end
answers
553-AAA1147
Description and Installation