Nortel Networks 553-3901-200 instruction manual Install the Silc and the Uilc

Page 42 of 46 Install ISDN BRI hardware

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, as follows: in

Table 8

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.

Install the SILC and the UILC

Follow the same procedures as described earlier for line applications (refer to “Install the BRSC, SILC and UILC” on page 21).

Connect Meridian 1 to the Main Distribution Frame (MDF)

Follow the same procedures as described earlier for line applications (refer to “Connect Meridian 1 modules to the MDF” on page 24).

Cross-connect the Main Distribution Frame (MDF)

The Meridian 1, 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.

553-3901-200 Standard 7.00 January 2002