Owner's manual

Applications 715

Table 283

Insertion Loss from IPE Ports to IPE Ports (measured in dB) (cont’d.)

The transmission properties of each trunk are characterized by

class-of-service (COS) assignments in the trunk data block (LD 14). The

assignment may be non-Via Net Loss (non-VNL) or via Net Loss (VNL). To

ensure stability and minimize echo when connecting to long-haul VNL (Tie)

trunks, non-VNL trunks are assigned either Transmission Compensated

(TRC) or Non-Transmission Compensated (NTC) class-of-service.

The TRC and NTC COS options determine the operation of the switchable

pads contained in the trunk circuits. They are assigned as follows:

• TRC for a two-wire non-VNL trunk facility with a loss of greater than 2

dB or for which impedance compensation is provided, or for a four-wire

non-VNL facility.

• NTC for a two-wire non-VNL trunk facility with a loss of less than 2 dB

or when impedance compensation is not provided.

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311 02.06 Standard

27 August 2008