Page418 of 544 NT6D70SILC line card
553-3011-100 Standard14.00 January 2002
S/T interface logic
The S/T interface logic consists of a transceiver circuit and the DSL power
source. This interface supports DSLs of different distances and different
number and types of terminals.
The transceiver circuits provide four-wire full duplex S/T bus interface. This
bus supports multiple physical terminations on one DSL where each physical
termination supports multiple logical B-channel and D-channel ISDN BRI
terminals. Idle circuit-switched B-channels can be allocated for voice or data
transmission to terminals making calls on a DSL. When those terminals
become idle, the channels are automatically made available to other terminals
making calls on the same DSL.
The power on the DSL comes from the SILC, which accepts -48 V from the
IPE backplane and provides 2 watts of power to physical terminations on each
DSL. It provides -48 V for ANSI compliant ISDN BRI terminals and -40 V
for CCITT (such as ETSI NET-3, INS NET-64) compliant terminals. The
total power used by the terminals on each DSL must not exceed 2 watts.
Physical description
The NT6D70 SILC is a standard size circuit card designed to be inserted in
peripheral equipment slots in the Meridian 1. Its faceplate is equipped with an
LED to indicate its status.
Power consumption
Power consumption is +5V at 800 mA and -48V 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.