Nortel Networks NN43001-318 - Manual (Page 42)

42 Installing ISDN BRI hardware
The SILC can recover the network clock from the received data stream
using on-chip phase lock loops. The clock frequency that is recovered is
2.56 MHz. The jitter and wander conform to CCITT recommendations.
All of the S/T chips on the SILC could be configured as Terminal Equipment
Slaves (TES), but only the clocks recovered from DSL0 and DSL1 are
routed to the back plane connector pins. These clocks are provided as
differential pairs on back plane pins. See
Table 9 "Clocks as differential
pairs" (page 42) .
Table 9
Clocks as differential pairs
Differential pairs Pin # Row A Row B
Primary 73 +Ref 0A - Ref 0A
Primary 74 +Ref 1A - Ref 1A
Secondary 75 +Ref 0B - Ref 0B
Secondary 76 +Ref 1B - Ref 1A
Automatic clock recovery is done upon the expiration of the free run guard
timer. Tracking is restored to the primary reference clock, if defined. If the
primary reference clock is disabled, tracking is restored to the secondary
reference clock, if defined.
Installing the SILC and the UILC
Follow the same procedures as described earlier for line applications (refer
to
Procedure 5 "Installing the BRSC, SILC, and UILC" (page 22) ).
Connecting the system to the Main Distribution Frame (MDF)
Follow the same procedures as described earlier for line applications (refer
to
Procedure 8 "Connect the modules to the MDF" (page 24) ).
Cross-connecting the Main Distribution Frame (MDF)
The system, in TIE trunk or CO connectivity, requires a different wiring
configuration than for a line application; the transmit and receive pairs should
be reversed, as illustrated in
Figure 12 "Connect the network termination to
the U interface and to the S/T interface (in TE mode)" (page 43) .
Nortel Communication Server 1000
ISDN Basic Rate Interface Installation and Commissioning
NN43001-318 01.02 Standard
Release 5.0 20 June 2007
Copyright © 2003-2007, Nortel Networks
.