Nortel Networks Circuit Card - Manual (Page 622)

Page 622 of 906 NT8D14 Universal Trunk card
553-3001-211 Standard 3.00 August 2005
Port-to-port loss configuration
Loss parameters are selected on the NT8D14 Universal Trunk card by a
switchable pad controlled by codec emulation software. For convenience, the
pads settings are called “in” and “out.” Pad settings are determined by the two
factors listed below (the first is under direct user control; the second is
controlled indirectly):
• Class of Service is assigned in LD 14 (under direct user control).
• Port-to-port connection loss is automatically set by software on the basis
of the port type selected in LD 16; only the port type is set by the user
(controlled indirectly).
The transmission properties of each trunk are characterized by the class of
service assigned in LD 14. Transmission properties can be Via Net Loss
(VNL) or non-Via Net Loss (non-VNL).
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 Transmission Compensated (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
Table 194
Cable loop resistance and loss
Cable length
Cable loop resistance (ohms)
Cable loop loss (dB)
(nonloaded at 1kHz)
22 AWG 24 AWG 26 AWG 22 AWG 24 AWG 26 AWG
915 m (3000 ft.) 97 155 251 0.9 1.2 1.5
1524 m (5000 ft.) 162 260 417 1.6 2.0 2.5
2225 m (7300 ft.) 236 378 609 2.3 3.0 3.7
3566 m (11700 ft.) 379 607 977 3.7 4.8 6.0
5639 m (18500 ft.) 600 960 1544 5.9 7.6 9.4