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