Nortel Enterprise 1000 Reference Manual page 55

Figure 13
Ground start call states – incoming call
Note 1: The far-end may reverse battery and ground upon receipt of attendant answer.
Note 2: The near-end provides a high-impedance (>150k ohms) disconnect signal of at
least 50 ms before reconnecting the ground detector.
Succession Communication Server for Enterprise 1000 Circuit Card Reference Guide
Analog Trunk Cards - NT8D14 Universal Trunk Card
Succession CSE 1000
High-resistance loop
Near-end
disconnects
Idle
Far-end
disconnects
Ringing
Far-end
originates
Near-end
disconnects
first (Note 2)
Assignment
to loop key
(near-end)
Low-resistance loop
Far-end
disconnects
Near-end
answers,
ringing is
removed
(Note 1)
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