Nortel Networks Circuit Card 311 User Manual
Page 760
760
NT8D15 E and M Trunk card
For descriptive purposes, the lead pair Tip B/Ring B is designated the
signaling pair. 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 273 "DX signaling - outgoing calls with originating party release" (page
760)
Table 274 "DX signaling - incoming calls with originating party
show call-connection and take-down sequencing for
DX signaling.
Table 275 "DX signaling - outgoing calls with originating party
release on tandem connections" (page 761)
and
- incoming calls with originating party release on tandem connections"
(page 761)
show sequencing where the E and M Trunk card is used in
a tandem PBX.
Table 273
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
Digits
Current flow interrupted
for each pulse
High
Far-end answers
No current flow
Low
Far-end on hook first
Current flow
High
Network taken down and trunk idled when
near-end goes on hook
No current flow
High
Near-end on hook first, network taken down
Current flow
Low
Far-end on hook, trunk idled
No current flow
High
Table 274
DX signaling - incoming calls with originating party release
Condition
Current in
signaling lead
State of trunk
detector
Idle
No current flow
High
Seizure
(dial tone to far-end: near-end ready for digits)
Current flow
Low
Digits
Current flow interrupted
for each pulse
Low-high-low
for each pulse
Near-end answers
No current flow
Low
Far-end on hook first
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
.