Avaya Nortel Communication Server 1000 Reference page 458

NT8D15 E and M Trunk card
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 Electronic Switched Network (ESN) are
recommended to be 4-wire for optimum transmission; so, 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 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.
SeeTable 194: Pad switching algorithm
various through connections and the actual port-to-port loss introduced for connections
between the E and M Trunk card and any other IPE port designated as Port B.
Figure 146: Pad orientation
Table 194: Pad switching algorithm
Port B
IPE line
Universal
trunk (TRC)
458 Circuit Card Reference
on page 459 shows the pad switching orientation.
Port B pads
Transmit Receive A
D to A to D
N/A N/A
Out Out
Comments? infodev@avaya.com
on page 458 for the pad switching control for the
E and M Trunk Pads
Transmit Receive A
D to A to D
Out In
In In
Port-to-port loss (dB)
Port B to E E and M to
and M Port B
2.5 3.5
0 0
July 2011