Nortel Networks Circuit Card - Manual (Page 380)

Page 380 of 906 NT6D70 SILC Line card
553-3001-211 Standard 3.00 August 2005
B-channels transmit user voice and data information at high speeds, while
D-channels are packet-switched links that carry call set-up, signaling and
other user data across the network.
One single DSL can carry two simultaneous voice or data conversations to the
same or to different locations. In either case, the D-channel can also be used
for packet communication to a third location simultaneously. The two
B-channels can also be combined to transmit data at uncompressed speeds of
up to 128 Kbps.
A wide range of devices and telephone numbers can be associated with a
single DSL to offer equipment flexibility and reduce line, wiring, and
installation costs.
Physical description
The NT6D70 SILC card is a standard-size circuit card. Its faceplate is
equipped with an LED to indicate its status.
Power consumption
Power consumption is +5 V at 800 mA and –48 V at 480 mA.
Foreign and surge voltage protections
In-circuit protection against power line crosses or lightning is not provided on
the SILC card. When the SILC card is used in TIE trunk applications in which
the cabling is exposed to outside plant conditions, an NT1 module certified
for such applications must be used. Check local regulations before providing
such service.
Functional description
The NT6D70 SILC card provides eight S/T four-wire full-duplex
polarity-sensitive interfaces to connect ISDN BRI-compatible terminals over
Digital Subscriber Loops (DSL) to the system. Each S/T interface provides
two B-channels and one D-channel and supports a maximum of eight physical
connections that can link up to 20 logical terminals on one DSL.