Two-way, loop dial repeating, tie trunk operation, Incoming calls – Nortel Networks 1000 User Manual

Page 537

Operation

537

Two-way, loop dial repeating, TIE trunk operation

Incoming calls

In an incoming call configuration, the far-end initiates a call by placing
a low-resistance loop across the tip and ring leads. See

Figure 159

"Two-way, loop DR, TIE trunk call states - incoming call from far-end PBX"
(page 538)

and

Figure 160 "Two-way, loop DR, TIE trunk call connection

sequence - incoming call from far-end PBX" (page 539)

This causes a current to flow through the battery feed resistors in the trunk
circuit. Address signaling is then applied by the far-end in the form of
DTMF tones or dial pulses. When the called party answers, an answer
supervision signal is sent by the software, causing the System to reverse
battery and ground on the tip and ringleads to the far-end. Far-end
disconnect is initiated by opening the loop while the near-end disconnect
is initiated by restoring normal battery and ground. The operation
represented in

Figure 159 "Two-way, loop DR, TIE trunk call states -

incoming call from far-end PBX" (page 538)

and

Figure 160 "Two-way,

loop DR, TIE trunk call connection sequence - incoming call from far-end
PBX" (page 539)

also applies to incoming DID trunk calls from a CO.

Note:

Where no near-end answer supervision is provided, the party at

the far-end hangs up after recognizing near-end call termination.

In an incoming call configuration, the far-end initiates a call by placing
a low-resistance loop across the tip and ring leads. See

Figure 161

"Two-way, loop DR, TIE trunk call states - incoming call from far-end PBX"
(page 540)

and

Figure 162 "Two-way, loop DR, TIE trunk call connection

sequence - incoming call from far-end PBX" (page 541)

This causes a current to flow through the battery feed resistors in the trunk
circuit. Address signaling is then applied by the far-end in the form of
DTMF tones or dial pulses. When the called party answers, an answer
supervision signal is sent by software, causing the Meridian 1 to reverse
battery and ground on tip and ring to the far-end. Far-end disconnect
is initiated by opening the loop while near-end disconnect is initiated
by restoring normal battery and ground. The operation represented in

Figure 161 "Two-way, loop DR, TIE trunk call states - incoming call from
far-end PBX" (page 540)

and

Figure 162 "Two-way, loop DR, TIE trunk call

connection sequence - incoming call from far-end PBX" (page 541)

also

applies to incoming DID trunk calls from a CO.

Note:

Where no near-end answer supervision is provided, the party at

the far-end hangs up, after recognizing near-end call termination.

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311