708 NT8D14 Universal Trunkcard
The VNL class of service is assigned at the prompt CLS with the response
VNL. The non-VNL class of service is assigned at prompt CLS by selecting
either the TransmissionCompensated (TRC) or Non-Transmission
Compensated (NTC) response.
Non-VNL trunks are assigned a TRC or NTC class of service to ensure
stability and minimize echo when connecting to long-haul trunks, such as
TIE 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 fora 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 Table264 "Pad switching algorithm" (page 708) for the pad switching
control for the various through connections and the actual port-to-port loss
introduced for connections between the Universal trunk card and any other
IPE or PE port designated as Port B.
Table264
Pad switching algorithm
Port B pads Universal Trunk
Pads Port-to-port loss (dB)
Port B Transmit
DtoA Receive
AtoD Transmi
DtoA Receive
AtoD
Port B to
Universal
trunk
card
Universal
trunk
card to
Port B
IPE line N/A N/A Out Out 0.5 0.5
Universal trunk (TRC) In Out In Out 11
IPE TIE (VNL) In In Out Out 00
PE line N/A N/A Out Out 11
Note 1: Transmit and receive designations are from and to the Meridian 1. Transmit is from the
Meridian 1 to the external facility (digital-to-analog direction in the Universal trunk card). Receive is
to the Meridian 1 from the external facility (analog-to-digital direction in the Universal
Note 2: 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.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright© 2003-2008, Nor tel Networks
.