Nortel Networks Video Gaming Accessories 553-3001-211 Manuale Utente

 NT8D14 Universal Trunk card

An incoming call from the CO places a low-resistance loop across the tip and 
ring leads. See Figure 120 on 

. 

Dial pulses or DTMF tones are then presented from the CO. When the called 
party answers, the universal trunk card reverses battery and ground on the tip 
and ring leads to the CO. The trunk is arranged for first party release. The CO 
releases the trunk by removing the low-resistance loop, at which time normal 
battery and ground are restored at the near-end. This also applies to incoming 
tie trunk calls from a far-end PBX.

Note: The near-end can be configured for immediate start, delay dial, or 
wink start.

 

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 122 on 

 

. 

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 122 on 

 and Figure 123 on 

 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.