Nortel Networks NN43001-301 manual Clock, DDP cable for systems with an I/O panel

70ISDN Primary Rate Interface equipment overview

Note: Since there exists several clock cabling options, none has been represented in the diagram. Please refer to "Clock configurations" (page

72)for a description on each available option.

Figure 29

DDP cable for systems with an I/O panel

Clock

There are two types of clock operation - tracking mode and free-run mode.

Tracking mode

In tracking mode, the DDP loop supplies an external clock reference to a clock controller. Two DDP loops can operate in tracking mode, with one defined as the primary reference source for clock synchronization, the other defined as the secondary reference source. The secondary reference acts as a back-up to the primary reference.

Nortel Communication Server 1000

ISDN Primary Rate Interface Installation and Commissioning

NN43001-301 02.03 Standard

Release 5.5 7 December 2007

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