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
on page 128).
Table 58: Call connection sequence-near-end station receiving call
State
Signal / Direction Far-end /
Near-end
Remarks
Line card unit
idle
Group on tip, battery on ring
High resistance loop
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.
Incoming call
Ringing
The system applies 20 Hz ringing to ring
lead.
Near-end
station off-hook
Low resistance loop
Two-way voice
connection
The system detects increase in loop
current, tips ringing, and put call through
to near-end station.
Near end station
hangs up first
High-resistance loop
If near end station hangs-up first, the
line card detects the drop in loop
current.
Line card unit
idle
Group on tip, battery on ring
High resistance loop
Line card unit is ready for the next call.
Far end station
hangs up first
High resistance loop
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
idle
Ground on tip/battery on ring
High resistance loop
Line card unit is ready for the next call.
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
Table 59: Call connection sequence-near-end station receiving call
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.
NT1R20 Off-Premise Station Analog Line card
128 Circuit Card Reference
July 2011
Summary of Contents for 1000 Series
Page 1: ...Circuit Card Reference Nortel Communication Server 1000 7 0 NN43001 311 04 04 July 2011 ...
Page 20: ...20 Circuit Card Reference July 2011 ...
Page 30: ...Introduction 30 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 116: ...Option settings 116 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 143: ...Figure 25 CP PIV card front Physical description Circuit Card Reference July 2011 143 ...
Page 148: ...NT4N39AA CP Pentium IV Card 148 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 287: ...Figure 86 Clock Controller Option 3 Operation Circuit Card Reference July 2011 287 ...
Page 302: ...NT5K21 XMFC MFE card 302 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 346: ...NT6D80 MSDL card 346 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 353: ...Figure 96 NTDK16 DLC Functional description Circuit Card Reference July 2011 353 ...
Page 461: ...Figure 147 Paging trunk operation Applications Circuit Card Reference July 2011 461 ...
Page 462: ...NT8D15 E and M Trunk card 462 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 500: ...NTAK09 1 5 Mb DTI PRI card 500 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 512: ...NTAK10 2 0 Mb DTI card 512 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 534: ...NTAK79 2 0 Mb PRI card 534 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 550: ...NTBK22 MISP card 550 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 560: ...NTBK50 2 0 Mb PRI card 560 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 595: ...Figure 165 MGC block diagram Introduction Circuit Card Reference July 2011 595 ...
Page 662: ...NTRB21 DTI PRI DCH TMDI card 662 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 668: ...NTVQ01xx Media Card 668 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 700: ......