
Page 48 of 906
Overview
553-3001-211 Standard 3.00 August 2005
Figure 9
Hook flash disconnect supervision sequence
High-
resistance
loop
Line card unit idle
(2-way voice
connection)
Remarks
Ground on tip/
battery on ring
Signal/direction
State
System
No battery current drawn.
Far-end station goes off hook and addresses
(dials up) near-end station. The system
receives the incoming call and determines that
the call is for a specific unit terminal number
(TN) and assigns message timeslots.
The system applies 20 Hz ringing to the ring
lead.
Ringing
Low-resistance loop
Near-end station
off hook
Near-end station goes off hook.
The system detects increase in loop current,
trips ringing, and cuts call through to near-end
station.
Alert
Call request
Line
card
Low-
resistance
loop
Far-end station
on hook
When the far-end station hangs up, the
following happens: The system detects
disconnect signalling from the far end, removes
the timeslot assignments, and sends a hook
flash (tip removed from ground) to the near-end
station.
Near-end
station on hook
Tip open/
battery on ring
Tip open/
battery on ring
The near-end station responds by going on
hook, presenting a high-resistance loop to the
system.
High-
resistance
loop
Line card unit idle
Ground on tip/
battery on ring
At the end of the hook-flash interval, the
system returns the tip to ground. The line
card unit is then ready for the next call. (Note 2)
High-
resistance
loop
Note 1:
Hook-flash signalling is a supervisory feature that is only used when the far-end station
originates and terminates the call. If the far-end station originates the call but the near-end
hangs up first, a hook flash is not sent.
Note 2:
If the end of the hook-flash interval occurs before the near-end station goes on hook, the
system waits until the near-end station does so before placing the line card unit in the
idle state.
553-AAA1116
Near-end
station
Far-end
station
Ground on tip/
battery on ring
Low-
resistance
loop
Содержание Circuit Card
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Страница 4: ...Page 4 of 906 Revision history 553 3001 211 Standard 3 00 August 2005...
Страница 18: ...Page 18 of 906 Contents 553 3001 211 Standard 3 00 August 2005...
Страница 78: ...Page 78 of 906 Overview 553 3001 211 Standard 3 00 August 2005...
Страница 100: ...Page 100 of 906 Acceptance tests 553 3001 211 Standard 3 00 August 2005...
Страница 156: ...Page 156 of 906 Option settings 553 3001 211 Standard 3 00 August 2005...
Страница 192: ...Page 192 of 906 NT4N39AA CP Pentium IV Card 553 3001 211 Standard 3 00 August 2005...
Страница 248: ...Page 248 of 906 NT5D11 and NT5D14 Lineside T1 Interface cards 553 3001 211 Standard 3 00 August 2005...
Страница 378: ...Page 378 of 906 NT5K21 XMFC MFE card 553 3001 211 Standard 3 00 August 2005...
Страница 384: ...Page 384 of 906 NT6D70 SILC Line card 553 3001 211 Standard 3 00 August 2005...
Страница 388: ...Page 388 of 906 NT6D71 UILC Line card 553 3001 211 Standard 3 00 August 2005...
Страница 533: ...NT8D02 and NTDK16 Digital Line cards Page 533 of 906 Circuit Card Description and Installation Figure 106 NTDK16 DLC...
Страница 544: ...Page 544 of 906 NT8D02 and NTDK16 Digital Line cards 553 3001 211 Standard 3 00 August 2005...
Страница 546: ...Page 546 of 906 NT8D03 Analog Line card 553 3001 211 Standard 3 00 August 2005...
Страница 564: ...Page 564 of 906 NT8D09 Analog Message Waiting Line card 553 3001 211 Standard 3 00 August 2005...
Страница 626: ...Page 626 of 906 NT8D14 Universal Trunk card 553 3001 211 Standard 3 00 August 2005...
Страница 680: ...Page 680 of 906 NT8D41AA Serial Data Interface Paddle Board 553 3001 211 Standard 3 00 August 2005...
Страница 694: ...Page 694 of 906 NT8D41BA Quad Serial Data Interface Paddle Board 553 3001 211 Standard 3 00 August 2005...
Страница 720: ...Page 720 of 906 NTAK09 1 5 Mb DTI PRI card 553 3001 211 Standard 3 00 August 2005...
Страница 734: ...Page 734 of 906 NTAK10 2 0 Mb DTI card 553 3001 211 Standard 3 00 August 2005...
Страница 744: ...Page 744 of 906 NTAK20 Clock Controller daughterboard 553 3001 211 Standard 3 00 August 2005...
Страница 762: ...Page 762 of 906 NTAK79 2 0 Mb PRI card 553 3001 211 Standard 3 00 August 2005...
Страница 768: ...Page 768 of 906 NTAK93 D channel Handler Interface daughterboard 553 3001 211 Standard 3 00 August 2005...
Страница 772: ...Page 772 of 906 NTBK22 MISP card 553 3001 211 Standard 3 00 August 2005...
Страница 844: ...Page 844 of 906 NTVQ01xx Media Card 553 3001 211 Standard 3 00 August 2005...
Страница 850: ...Page 850 of 906 NTVQ55AA ITG Pentium card 553 3001 211 Standard 3 00 August 2005...
Страница 884: ...Page 884 of 906 QPC841 Quad Serial Data Interface card 553 3001 211 Standard 3 00 August 2005...
Страница 906: ...Page 906 of 906 Appendix A LAPB Data Link Control protocol 553 3001 211 Standard 3 00 August 2005...
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