Nortel Networks 1000 - Manual (Page 904)

904 NTCK16 Generic Central Office Trunk cards
•
Loss Switching
• Trunk-to-Trunk connections
• Call Disconnect
In addition, the NTCK16AX circuit card supports internal 12/16 kHz PPM
detection.
Loop start operation
Loop start operation is configured in software and is implemented in the
card through software download messages.
Idle state
In the idle state, the ringing detector is connected across the tip and ring
wires, providing a high impedance loop toward the Central Office.
Call placed by Central Office
The Central Office initiates a call by applying ringing between the tip and
ring wires. If the call is answered, the ringing detector on the trunk card
is switched out and a low resistance dc loop is placed between the tip
and ring leads.
On trunks configured for battery supervision, the battery detector records
the polarity of the tip and ring wires and sends an answer acknowledge
signal to software.
Call placed by CS 1000E, CS 1000M, and Meridian 1
To initiate a call, the CS 1000E, CS 1000M, and Meridian 1switches out
the ringing detector and places a low resistance loop across the tip and
ring leads. On trunks configured for battery supervision, the trunk card
sends a seize acknowledge signal to software.
The system sends digits in the form of Dual Tone Multifrequency (DTMF)
tones or pulse digits. When the far-end answers, the Central Office
reverses polarity. If the trunk is configured for battery supervision, it sends
a polarity reversal message to software.
Central Office disconnect
There are two ways the Central Office can disconnect the call:
• by applying busy tone toward the CS 1000E, CS 1000M, and Meridian
1. If the trunk card is configured to detect busy tone, it sends a
disconnect message to software.
• by reversing battery. If the trunk card is configured to detect battery
reversal, it sends a disconnect message to software. When the unit on
the trunk card is idled, the trunk card sends a release confirm message
to software.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.