Nortel Networks 553-3001-211 manual Clock controller interface, Clock rate converter

NTAK09 1.5 Mb DTI/PRI card Page 707 of 894

Table 228

DS-1 line interface pinout for NTBK04 cable (Part 2 of 2)

From 50-pin MDF
connector	To DB-15	Signal name	Description
pin 49	pin 3	T1	receive tip from network
pin 24	pin 11	R1	receive ring from network

Clock controller interface

The clock controller interface provides the recovered clock from the external digital facility to the clock controller daughterboard through the backplane. Depending on the equipped state of the clock controller, the clock controller interface enables or disables the appropriate reference clock source, in conjunction with software.

IMPORTANT!

Each MG 1000S that has a digital trunk must have a clock controller clocked to an external reference clock.

Note: Clocking slips can occur between MG 1000S systems that are clocked from different Central Offices (COs), if the COs are not synchronized. The slips can degrade voice quality.

Clock rate converter

The 1.5 Mb clock is generated by a Phase-Locked Loop (PLL). The PLL synchronizes the 1.5 Mb DS1 clock to the 2.56 Mb system clock through the common multiple of 8 kHz by using the main frame synchronization signal.

Circuit Card Description and Installation