Nortel Enterprise 1000 Reference Manual page 75

Analog Trunk Cards - NT8D14 Universal Trunk Card Page 75 of 236
Figure 27
Two-way, loop OAID, tie trunk call states – incoming call from far-end PBX
Succession CSE 1000 (near-end)
Ground on tip, Battery on tip,
battery on ring ground on ring
Idle
Forced
near-end
disconnects
Far-end
disconnects
first
Far-end
disconnect
Near-end
disconnects
first
Battery-ground
or loop pulses,
Near-end
or DTMF answers
Far-end
originates
553-CSE6251
Succession Communication Server for Enterprise 1000 Circuit Card Reference Guide