Nortel Circuit Card Installation Manual page 623

Table 195
Pad switching algorithm
Port B
IPE line
Universal trunk
(TRC)
IPE TIE (VNL)
Note: Transmit and receive designations are from and to the system. Transmit is from the
system to the external facility (digital-to-analog direction in the Universal trunk card). Receive is
to the system from the external facility (analog-to-digital direction in the Universal trunk card).
Note: When Port B is the call originating port. If the Universal trunk card is the originating port,
the UTC pads are out, the Port B (PE CO/FX/WATS) pads are in.
trunks. The class of service determines the operation of the switchable pads
contained in each unit. They are assigned as follows:
• TRC for a 2-wire non-VNL trunk facility with a loss of greater than 2 dB,
or for which impedance compensation is provided, or for a 4-wire
non-VNL facility.
• NTC for a 2-wire, non-VNL trunk facility with a loss of less than 2 dB,
or when impedance compensation is not provided.
See Table 195 for the pad switching control for the various through
connections and the actual port-to-port loss introduced for connections
between the NT8D14 Universal Trunk card and any other port designated as
Port B.
Port B pads
Transmit Receive
D to A A to D
N/A N/A
In Out
In In
NT8D14 Universal Trunk card
Universal Trunk
Pads
Transmit Receive
D to A A to D
Out Out
In Out
Out Out
Circuit Card
Page 623 of 906
Port-to-port loss (dB)
Port B to Universal
Universal trunk
trunk card to
card Port B
0.5 0.5
1 1
0 0
Description and Installation