Nortel Networks 553-3001-211 manual 564 of 894 NT8D14 Universal Trunk card

Page 564 of 894 NT8D14 Universal Trunk card

Figure 114

Ground start call states – incoming call from CO/FX/WATS

System (near) end

CO / FX / WATS (far) end

Tip open,	battery on ring
Ground on tip,	battery on ring

High-resistance loop		Low-resistance loop
	Near end
Idle	disconnects
		far end
	Far end	disconnects
	disconnects	first
	Near end
	disconnects
	first (Note 2)
		Near end
	Ringing	answers,
		ringing is
Far end	Assignment	removed
originates	to loop key	(Note 1)

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.

553-AAA1133

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.

553-3001-211 Standard 2.00 September 2004