Nortel Networks Circuit Card User Manual

 NT6D70 SILC Line card

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.

The NT6D70 SILC card is a standard-size circuit card. Its faceplate is 
equipped with an LED to indicate its status.

Power consumption is +5 V at 800 mA and –48 V at 480 mA.

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.

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.