Nortel Networks NN43001-301 - Manual (Page 268)

268 2.0 Mb PRI implementation
For the U.K., use DPNSS1 mode. For all other countries, use Q.931 mode.
Table 98
Switch SW1
Switch Down (On) Up (Off)
SW 1-1 — —
SW 1-2 DPNSS1/DASS2 Q.931
Switch SW2 - Carrier impedance configuration
This switch sets the carrier impedance to either 120 1 /
2
or 75 1 /
2
. Twisted pair
cable is usually associated with 120 1 /
2
. Coaxial cable is usually associated
with the 75 1 /
2
setting.
Table 99
Switch SW2
Cable type SW 2-1
75 3 /
4
Down (On)
120 3 /
4
Up (Off)
Switch SW4 - Carrier shield grounding
This switch supports the selective grounding of Tx and Rx pairs of carrier
cable. Closing the switch (down position) applies Frame Ground (FGND) to
the coaxial carrier cable shield, creating a 75
1 /
2
unbalanced configuration.
This applies only to the NTBK05CA cable.
Table 100
Switch SW3
Switch Down (On) Up (Off)
SW 4-1 Rx—FGND Rx—OPEN
SW 4-2 Tx—FGND Tx—OPEN
Note: The usual method is to ground the outer conductor of the receive
coax signal.
Mount the daughterboards on the NTBK50
Use the following procedure to mount and remove the NTAK20 CC and the
NTBK51 DDCH or NTAK93 DCHI daughterboards onto the NTBK50 PRI.
Install the NTAK93 or NTBK51 daughterboard before the NTAK20
daughterboard. Work on a flat surface when mounting or removing
daughterboards.
Nortel Communication Server 1000
ISDN Primary Rate Interface Installation and Commissioning
NN43001-301 02.03 Standard
Release 5.5 7 December 2007
Copyright © 2003-2007, Nortel Networks
.