Page416 of 544 NT6D70SILC line card
553-3011-100 Standard14.00 January 2002
Functional description
The SILC provides eight S/T four wire full duplex polarity sensitive
interfaces that are used to connect ISDN BRI compatible terminals over
Digital Subscriber Loop s (DSL) to the Meridian 1. Ea ch 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.
A logical terminal is any terminal that can communicate with the Meridian 1
over a DSL. It may be directly connected to the DSL through its own physical
termination or be indirectly connected through a common physical
termination.
The length of a DSL depends on the specific terminal configuration and the
DSL wire gauge, however, it should not exceed 1 km (3,280 ft).
The SILC interface uses a 4 conductor cable that provides a differential
Transmit and Receive pa ir for each DSL. The SIL C has options to provi de a
total of 2 Watts of power on the Transmit or Receive leads, or no power at all.
When this power is supplied from the S/T interface, the terminal devices must
not draw more than the 2 Watts of power. Any power requirements beyond
this limit must be locally powered.
Other functions of the SILC are:
•support point-to-point and multi-point DSL terminal connections
•execute instructions received from the MISP to configure and control the
S/T interfaces
•provide channel mapping between ISDN BRI format (2B+D) and
Meridian 1 system bus format
•multiplexes 4 D-channels onto one timeslot
•perform activation and deactivation of DSLs
•provide loopback control of DSLs
•provide a reference clock to the clock controller