Outgoing Calls - Avaya Nortel Communication Server 1000 Reference

NT1R20 Off-Premise Station Analog Line card
resistance DC loop across the tip and ring leads toward the OPS analog line card. (see
58: Call connection sequence-near-end station receiving call
Table 58: Call connection sequence-near-end station receiving call
State
Line card unit
idle
Incoming call
Near-end
station off-hook
Two-way voice
connection
Near end station
hangs up first
Line card unit
idle
Far end station
hangs up first
Line card unit
idle

Outgoing calls

For outgoing calls from a telephone, a line unit is seized when the telephone goes off-hook,
placing a low-resistance loop across the tip and ring leads towards the NT1R20 OPS analog
line card (see
page 129). When the card detects the low-resistance loop, it prepares to receive digits. When
the system is ready to receive digits, it returns a dial tone. Outward address signaling is then
applied from the telephone in the form of loop (interrupting) dial pulses or DTMF tones.
128 Circuit Card Reference
Signal / Direction Far-end /
Near-end
Group on tip, battery on ring
High resistance loop
Ringing
Low resistance loop
High-resistance loop
Group on tip, battery on ring
High resistance loop
High resistance loop
Ground on tip/battery on ring
High resistance loop
Table 59: Call connection sequence-near-end station receiving call
Comments? infodev@avaya.com
on page 128).
Remarks
No battery current drawn.
Far-end station goes off-hook and
addresses (dials-up) the near-end
station. The system receives the
incoming call on a trunk and determine
the TN.
The system applies 20 Hz ringing to ring
lead.
The system detects increase in loop
current, tips ringing, and put call through
to near-end station.
If near end station hangs-up first, the
line card detects the drop in loop
current.
Line card unit is ready for the next call.
If the far-end hangs-up first, the system
detects disconnect signalling from the
trunk. The person at the near-end
recognizes the end of the call and
hangs-up.
Line card unit is ready for the next call.
Table
on
July 2011