
Page 578 of 906
NT8D14 Universal Trunk card
553-3001-211 Standard 3.00 August 2005
Ground start operation
Ground start operation is configured in software and implemented through
software download messages. In the idle state, the tip conductor from the CO
is open and a high-resistance negative battery is present on the ring lead.
Incoming calls
In an incoming call, after ground is detected on the tip, the universal trunk
card scans for a ringing detection signal before presenting the call to an
attendant and tripping the ringing. When the attendant answers, a low
resistance is placed across the tip and ring conductors, which trips CO ringing
and establishes a speech path. See Figure 119 on
page 579
and Figure 120 on
page 580
.
Reverse-wiring compensation
The CS 1000 Release 4.5 software includes a feature for detecting reverse
wiring (connection of the near-end tip and ring leads to the far-end ring and
tip leads) on ground start trunks with far-end answer supervision.
Ordinarily, an incoming call on a reverse-wired trunk without reverse-wiring
compensation presents ringing on the tip lead rather than on the ring lead.
Since the software expects to see a ground on the tip lead, it interprets the end
of the first ringing signal as a switchhook flash. But since the interval between
ringing signals exceeds the switchhook flash time of 512 milliseconds, the
software assumes a far-end disconnect. This causes the call to be presented to
a console loop key and then immediately removed.
The reverse-wiring compensation feature operates as follows. If an apparent
disconnect takes place immediately after the first ringing signal, the software
time stamps the event and temporarily remove the call from the console loop
key.
If another such ringing/disconnect event occurs during the No Ringing
Detector (NRD) time, the trunk is considered “possibly reverse-wired” and a
threshold counter starts. Calls on trunks identified as possibly reverse-wired
are presented to the attendant during the initial ring, removed, and then
continuously presented after the second ring. If a call on a possibly
reverse-wired trunk is abandoned before the attendant answers, it is
disconnected after the NRD timer expires.
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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