Operation 621
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 175 "Two-way,
loop DR, TIE trunk call states - incoming call from far-end PBX" (page
622) and Figure 176 "Two-way, loop DR, TIE trunk call connection sequence
- incoming call from far-end PBX" (page 623).
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 reversebatter y 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 175 "Two-way, loop DR, TIE trunk call states - incoming call from
far-end PBX" (page 622) and Figure 176 "Two-way, loop DR, TIE trunk call
connection sequence - incoming call from far-end PBX" (page623) 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 177 "Two-way,
loop DR, TIE trunk call states - incoming call from far-end PBX" (page
624) and Figure 178 "Two-way, loop DR, TIE trunk call connection sequence
- incoming call from far-end PBX" (page 625).
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 toreverse 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 177 "Two-way,
loop DR, TIE trunk call states - incoming call from far-end PBX" (page
624) and Figure 178 "Two-way, loop DR, TIE trunk call connection sequence
- incoming call from far-end PBX" (page 625) 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 01.04 Standard
Release 5.0 23 May 2008
Copyright© 2003-2008, Nor tel Networks
.