Nortel Networks NN43001-301 - Manual (Page 164)

164 Clock Controller description and installation
Figure 63
Example 4, Alternate Clocking from the same CO
In this case, a digital connection to the Central Office can exist (i.e. Loops X
and Y). When a second Digital loop from the CO or Master M-1 becomes
available, it can be used as a Secondary Clock Source in case the Primary
Source fails.
To avoid timing loops, in example 4-4 the most reliable slave system should
not have a Secondary Clock Source (SREF= ). In this example, this is
illustrated by the node which supports loops X and Z.
Nortel Communication Server 1000
ISDN Primary Rate Interface Installation and Commissioning
NN43001-301 02.03 Standard
Release 5.5 7 December 2007
Copyright © 2003-2007, Nortel Networks
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