Figure 117 on – Nortel Networks Circuit Card User Manual
Page 576
Page 576 of 906
NT8D14 Universal Trunk card
553-3001-211 Standard 3.00 August 2005
For trunks not equipped with answer supervision, the PIP class of service is
enabled and call-duration recording begins immediately upon near-end trunk
seizure. The PSP and PIP classes of service are enabled in the Trunk
Administration program LD 14.
Figure 117
Ground start call states – incoming call from CO/FX/WATS
System (near) end
High-resistance loop
Tip open,
battery on ring
Ground on tip,
battery on ring
CO / FX / WATS (far) end
Ringing
Far end
originates
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.
Idle
Near end
disconnects
Far end
disconnects
Near end
disconnects
first (Note 2)
far end
disconnects
first
Assignment
to loop key
Near end
answers,
ringing is
removed
(Note 1)
553-AAA1133
Low-resistance loop