Nortel Networks 1000 - Manual (Page 127)

Operation 127
The operation of each unit is configured in software and implemented in
the card through software download messages. When the NT1R20 OPS
analog line card unit is idle, it provides a ground on the tip lead and –48 V
dc on the ring lead. The on-hook telephone presents a high impedance
toward the line interface unit on the card.
The applications, features, and signaling arrangements for each unit on
the OPS analog line card are assigned through the Single-line Telephone
Administration program (LD10) and/or jumper strap settings on the card.
The operation of each unit is configured in software and is implemented in
the card through software download messages. When the OPS analog
line card unit is idle, it provides a ground on the tip lead and – 48 V dc on
the ring lead. The on-hook telephone presents a high impedance toward
the line interface unit on the card.
The applications, features, and signaling arrangements for each unit on
the NT1R20 OPS Analog Line Card are assigned through the Single-line
Telephone Administration program LD 10 and/or jumper strap settings on
the card.
The operation of each unit is configured in software and implemented in
the card through software download messages. When the NT1R20 OPS
Analog Line Card unit is idle, it provides a ground on the tip lead and –48
V dc on the ring lead. The on-hook telephone presents a high impedance
toward the line interface unit on the card.
Incoming calls
Incoming calls to a telephone connected to the NT1R20 OPS analog
line card originate from stations that can be local (served by the PBX)
or remote (served through the public switched telephone network). The
alerting signal to telephones is 20 Hz (nominal) ringing. When an incoming
call is answered, ringing is tripped as the telephone goes off-hook, placing
a low-resistance dc loop across the tip and ring leads toward the OPS
analog line card. (see
Table 54 "Call connection sequence-near-end
station receiving call" (page 128) ).
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.