Service change entries – Nortel Networks 1000 User Manual
Page 612
612
NT8D14 Universal Trunk card
shows jumper locations on
the universal trunk card (vintage BA).
Service change entries
The trunk type, terminating impedance, and balance network are selected
by making service change entries in the Trunk Administration program LD
14.
See
Table 227 "Trunk types - termination impedance and balance network
(NT8D14BA, NT8D14BB)" (page 612)
for the proper values for the trunk
type and loop length. Refer to Software Input/Output Reference —
Administration (NN43001-611) for LD 14 service change instructions.
Before the appropriate balance network can be selected, the loop length
between the near-end and the far-end (a Central Office, for example) must
be known. To assist in determining loop length, some typical resistance
and loss values for the most common cable lengths are given in
"Cable loop resistance and loss" (page 613)
for comparison with values
obtained from actual measurements.
Table 227
Trunk types - termination impedance and balance network (NT8D14BA, NT8D14BB)
Balance network for loop lengths (Note 2)
Trunk types
Terminating
impedance
(Note 1)
0–915 m
(0–3000 ft)
915–1524 m
(3000–5000 ft)
> 1524 m
(> 5000 ft)
CO/FX/WATS
600 or 900
ohms
600 ohms
3COM
3CM2
2-way TIE (LDR)
600 or 900
ohms
600 ohms
3COM
3CM2
2-way TIE (OAID)
600 or 900
ohms
600 ohms
3COM
3CM2
DID (loop length <
600 ohms)
600 or 900
ohms
600 ohms
3COM
3CM2
DID (loop length ˇ
S
600 ohms)
600 or 900
ohms
600 ohms
N/A
3CM2
Note 1: The terminating impedance of each trunk unit is software selectable in LD 14 and should
match the nominal impedance of the connecting equipment.
Note 2: The balance network of each trunk unit is software selectable between resistive 600 or
900 ohms or 3COM and jumper selectable between 3COM and 3CM2. Jumper selection for
3COM/3CM2 restriction does not apply to NT8D14BB.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311
02.06
Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.