Nortel Networks Circuit Card 311 User Manual

Page 693

Configuration

693

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)

RAN: continuous
operation mode

600 or 900
ohms

600 or 900 ohms

N/A

Paging

600 ohms

N/A

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.

The trunk type for each unit on the card as well as its terminating impedance
and balance network configuration is selected by software service change
entries at the system terminal and by jumper strap settings on the card.

NT8D14BB (Release 10 and higher) has a reduced jumper strap setting
on the card. There are only three jumpers, J1.X, J2.X, and J3.X per
channel.

Table 255 "Jumper strap settings - factory standard (NT8D14BA,

NT8D14BB)" (page 698)

Table 256 "Jumper strap settings - extended

range (NT8D14BA, NT8D14BB, NT8D14BB Release 10 and up)" (page
698)

, and

Table 257 "Trunk types - termination impedance and balance

network (NT8D14BA, NT8D14BB)" (page 699)

show the functionality of

these 3 jumpers.

NT8D14BB (Release 10 and higher) has a reduced jumper strap setting
on the card. There are only three jumpers, J1.X, J2.X, and J3.X on each
channel.

Table 255 "Jumper strap settings - factory standard (NT8D14BA,