Nortel Networks 553-3001-211 manual Software service entries, Port-to-port loss configuration

NT8D15 E&M Trunk card Page 649 of 894

Software service entries

The trunk type is selected by making service change entries in Route Data Block, Automatic Trunk Maintenance (LD 16). The companding mode is selected by making service change entries in Trunk Data Block (LD 14).

Refer to Table 203 on page 648 to select the proper values for the trunk type being employed.

Port-to-port loss configuration

Loss parameters are selected on the E&M trunk card by a switchable pad controlled by CODEC emulation software. The pads settings are called “in” and “out.” Pad settings are determined by the three factors listed below (the first two are under direct user control; the third is controlled indirectly):

•Class of Service is assigned in LD 14.

•Facility termination is selected (2-wire or 4-wire) in LD 14 (the 2-wire setting provides 0.5 dB more loss in each direction of transmission for echo control).

Note: Facilities associated with the Nortel Networks Electronic Switched Network (ESN) are recommended to be 4-wire for optimum transmission; thus, the 4-wire setting is generally referred to as the ESN setting. However, the 4-wire setting is not restricted to networks using the ESN feature. Conversely, the 2-wire setting, often called non-ESN, can be used on certain trunks in an ESN environment.

•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.

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 CLS prompt by typing VNL. The non-VNL class of service is assigned at the CLS prompt by typing TRC (Transmission Compensated) or NTC (Non-Transmission Compensated).

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

Circuit Card Description and Installation