Nortel Circuit Card Installation Manual page 383

NT6D70 SILC Line card Page 383 of 906
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 two 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
two watts.
Circuit Card Description and Installation