Computer Hardware Installation Guide

762 NT8D15 E and M Trunk card
Condition
Current in
signaling lead
State of trunk
detector
Stored digits outpulsed on CO/FX/WATS trunk
after ground detection if a ground start, but after
3 seconds if a loop start
If answer supervision: pseudo-answer
supervision is sent approximately 13 seconds
after last dial pulse received
No current flow Low
If no answer supervision: CO end disconnects
(if a CO ground start – the trunk is idled and
network taken down, but the incoming TIE trunk
is held under control of the originating end)
Current flow Low
Originating end disconnects – network taken
down and trunk idled
No current flow High
Note: * – CO ground start: the trunk is idled and the network taken
down, but the incoming tie trunk is controlled by the originating end.
Duplex (DX) signaling uses the voice transmission leads for signaling as
well as for voice transmission. See "SDI function" (page 1118).
For descriptive purposes, the lead pair Tip B/Ring B is designated the
signaling pair, whereas the other pair Tip A/Ring A conducts current in the
opposite direction to balance the overall current flow between the near and
far-ends. During signaling, current flows through both Tip B and Ring B
leads in the same direction.
Table 277 "DX signaling - outgoing calls with originating party release" (page
762) and Table 278 "DX signaling - incoming calls with originating party
release" (page 763) show call-connection and take-down sequencing for
DX signaling. Table 279 "DX signaling - outgoing calls with originating party
release on tandem connections" (page 763) and Table 280 "DX signaling
- incoming calls with originating party release on tandem connections"
(page 764) show sequencing where the E and M Trunk card is used in
a tandem PBX.
Table 277
DX signaling - outgoing calls with originating party release
Condition
Current in
signaling lead
State of trunk
detector
Idle No current flow High
Seizure
(dial tone from far-end: far-end ready for digits)
Current flow High
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.