Nortel Enterprise 1000 Reference Manual page 91

Table 13
Trunk types – termination impedance and balance network (NT8D14BA, NT8D14BB)
Trunk types
CO/FX/WATS
2-way tie (LDR)
2-way tie (OAID)
DID (loop length
< 600 ohms)
DID (loop length
Š 600 ohms)
RAN: continuous
operation mode
Paging
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 (Release 10 and later).
Table 14
Cable loop resistance and loss
Cable length
915 m (3000 ft)
1524 m (5000 ft)
2225 m (7300 ft)
3566 m (11700 ft)
5639 m (18500 ft)
Succession Communication Server for Enterprise 1000 Circuit Card Reference Guide
Analog Trunk Cards - NT8D14 Universal Trunk Card
Terminating
impedance
(Note 1)
(0–3000 ft)
600 or 900
600 ohms
ohms
600 or 900 600 ohms
ohms
600 or 900 600 ohms
ohms
600 or 900 600 ohms
ohms
600 or 900 600 ohms
ohms
600 or 900 600 or 900 ohms
ohms
600 ohms 600 ohms
Cable loop resistance (ohms)
22 AWG 24 AWG
97 155
162 260
236 378
379 607
600 960
Balance network for loop lengths (Note 2)
0–915 m 915–1524 m
(3000–5000 ft)
26 AWG
251
417
609
977
1544
3COM
3COM
3COM
3COM
N/A
N/A
N/A
Cable loop loss (dB)
(nonloaded at 1kHz)
22 AWG 24 AWG
0.9 1.2
1.6 2.0
2.3 3.0
3.7 4.8
5.9 7.6
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> 1524 m
(> 5000 ft)
3CM2
3CM2
3CM2
3CM2
3CM2
N/A
N/A
26 AWG
1.5
2.5
3.7
6.0
9.4