Nortel Networks Option 11C User Manual
Page 416 of 544
NT6D70 SILC line card
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 Loops (DSL) to the Meridian 1. 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.
interfaces that are used to connect ISDN BRI compatible terminals over
Digital Subscriber Loops (DSL) to the Meridian 1. 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.
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.
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).
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 pair for each DSL. The SILC has options to provide 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.
Transmit and Receive pair for each DSL. The SILC has options to provide 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
S/T interfaces
•
provide channel mapping between ISDN BRI format (2B+D) and
Meridian 1 system bus format
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