Ac15 Trunk Operation (2280 Hz Tie Trunk) - Northern Telecom NT5K17 Description

Table 3-4
Summary of NT5K19 DC-5 signalling states
Si gna l
I dl e
Sei z e
Ho ld
Di al i ng:
Di gi t Pu ls e
DT MF
Ans wer
Fa r End Rel eas e
Ne ar End Rel eas e

AC15 trunk operation (2280 Hz Tie trunk)

United Kingdom United Kingdom United Kingdom
United Kingdom United Kingdom United Kingdom
Out g oi ng PB X sen di ng
co ndi t io n — M W ir e
Ear t h-O ff
Ear t h-O n
Co nti nuat i on of s ei ze si gnal
Ear t h-O ff pul s es in s tep wi t h
di al pul ses
DT MF di gi t s
—
Ear t h-O ff f or l onger than 300
mi l l i s econds
—
The NT5K19 Analog Tie trunk card supports the United Kingdom
AC15-A method of signalling, which is used between two PBX machines.
The system is based on a single voice frequency, 2280 Hz, method of
signalling.
In this system, four signalling wires are used: one pair for forward signals
and one pair for backward signals. The transmit pair through which signals
are transmitted is the receive pair at the far end. All signals are in the form
of either tone-on or tone-off. Table 3-5 provides a summary of signals in
both transmit and receive directions.
NT5K19 Analog Tie Trunk Card 3-9
I ncomi ng PB X s end ing
co ndi t io n — M W ir e
Ear t h-O ff
—
—
—
—
Ear t h-O n
—
Ear t h-O ff f or l onger than
300 mi l l i sec onds
UK Trunk cards description 553-3001-173