Nortel Networks Circuit Card Benutzerhandbuch
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NT8D15 E&M Trunk card
trunks. The class of service determines the operation of the switchable pads
contained in each unit. They are assigned as follows:
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.
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.
or when impedance compensation is not provided.
See Table 209 for the pad switching control for the various through
connections and the actual port-to-port loss introduced for connections
between the E&M trunk card and any other IPE port designated as Port B.
connections and the actual port-to-port loss introduced for connections
between the E&M trunk card and any other IPE port designated as Port B.
shows the pad switching orientation.
Table 209
Pad switching algorithm
Pad switching algorithm
Port B
Port B pads
E&M Trunk Pads
Port-to-port loss (dB)
Transmit
D to A
Receive
A to D
Transmit
D to A
Receive
A to D
Port B to
E&M
E&M to
Port B
IPE line
N/A
N/A
Out
In
2.5
3.5
Universal trunk
(TRC)
(TRC)
Out
Out
In
In
0
0
IPE TIE (VNL)
In
Out
In
Out
0
0
Note: Transmit and receive designations are from and to the system. Transmit is from the
system to the external facility (digital-to-analog direction in the E&M trunk card). Receive is to
the system from the external facility (analog-to-digital direction in the E&M trunk card).
system to the external facility (digital-to-analog direction in the E&M trunk card). Receive is to
the system from the external facility (analog-to-digital direction in the E&M trunk card).