Nortel Enterprise 1000 Reference Manual page 58

Page 58 of 236 Analog Trunk Cards - NT8D14 Universal Trunk Card
553-3023-211 Standard 1.00 June 2001
detected by the card, a low-resistance path is placed between the tip and ring
leads and the ground is removed from the ring. Addressing is then applied
from the Succession CSE 1000 in the form of loop (interrupting) dial pulses
or DTMF tones. See Figure 15 on page 59 and Figure 16 on page 60.
The Polarity-Sensitive/Polarity-Insensitive Packs (PSP and PIP) feature must
be set to provide for proper outgoing call-duration recording with ground start
operation. Refer to the description of loop start operation in this section for a
more complete discussion of PSP and PIP.