Nortel Networks NN43001-301 - Manual (Page 159)

Description 159
In an isolated private network, the clock controller can operate in free run
mode and act as a master clock to be tracked by other PBX systems in
the private network.
Hierarchical synchronization
Figure 59 "Hierarchical Synchronization" (page 159) provides a general
view of the Digital Network Clock Synchronization including the four stratum
level Node Categories. Stratum 1 being the most accurate and Stratum 4
being the least accurate. System clocking meets Node Category E Stratum
4 requirements. Also shown are ways of providing a Secondary Clock
Source while preventing timing loops.
Figure 59
Hierarchical Synchronization
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
.