696 NT8D14 Universal Trunkcard
(NT8D14BA, NT8D14BB, NT8D14BB Release 10 and up)" (page 698).
Figure 218 "Universal trunk card - jumper locations for NT8D14BA and
NT8D14BB Release 9 and below" (page 702) 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 TrunkAdministration program LD 14.
See Table253 "Trunk types - termination impedance and balance network
(NT8D14BA, NT8D14BB)" (page 696) 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 forthe most common cable lengths are given in Table 254
"Cable loop resistance and loss" (page 697) for comparison with values
obtained from actual measurements.
Table253
Trunktypes - 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 01.04 Standard
Release 5.0 23 May 2008
Copyright© 2003-2008, Nor tel Networks
.