Ground Start Operation - Avaya Nortel Communication Server 1000 Reference

NT8D14 Universal Trunk card

Ground start operation

Ground start operation is configured in software and implemented through software download
messages. In the idle state, the tip conductor from the CO is open and a high-resistance
negative battery is present on the ring lead.
Incoming calls
In an incoming call, after ground is detected on the tip, the universal trunk card scans for a
ringing detection signal before presenting the call to an attendant and tripping the ringing. When
the attendant answers, a low resistance is placed across the tip and ring conductors, which
trips CO ringing and establishes a speech path. See
incoming call from CO/FX/WATS
sequence - incoming call from CO/FX/WATS
Figure 109: Ground start call states - incoming call from CO/FX/WATS
390 Circuit Card Reference
on page 390 and
on page 391.
Comments? infodev@avaya.com
Figure 109: Ground start call states -
Figure 110: Ground start call connection
July 2011