Owner's manual

974 NTRB21 DTI/PRI/DCH TMDI card
• receive clock output
• transmit clock output
The bit rate of the receive and transmit clocks can vary slightly from each
other. This is determined by the transmit and receive carrier clocks.
Feature selection through software configuration for the D-channel
includes:
•
56 kbps
•
64 kbps clear
• 64 kbps inverted (64 Kbps restricted)
DCHI can be enabled and disabled independent of the PRI card, as long
as the PRI card is inserted in its cabinet slot. The D-channel data link
cannot be established unless the PRI loop is enabled.
On the NTRB21 use switch 1, position 1 to select either the D-channel
feature or the DPNSS feature, as follows:
OFF = D-channel
The ON setting for DPNSS (U.K.) is not supported at this time.
DS-1 Carrier interface
Transmitter
The transmitter takes the binary data (dual unipolar) from the PCM
transceiver and produces bipolar pulses for transmission to the external
digital facility. The Digital Signal – Level 1 (DS-1) transmit equalizer
enables the cabling distance to be extended from the card to the Digital
Signal Cross-connect – Level 1 (DSX-1), or LD-1. Equalizers are switch
selectable through dip-switches. The settings are shown in Table 409
"NTRB21 switch settings" (page 974).
Table 409
NTRB21 switch settings
Switch Setting
Distance to Digital
Cross-Connect
1
DCH F/W
2
(LEN 0)
3
(LEN 1)
4
(LEN 2)
0 - 133 feet Off Off Off On
133 - 266 feet Off On On Off
266 - 399 feet Off Off On Off
399 - 533 feet Off On Off Off
533 - 655 feet Off Off Off Off
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.