5.26.1.1. Clock Hierarchy Plan 
The specific requirements of the network provider and the customers
result in the best synchronization strategy which can, in turn, lead
to certain decisions regarding the network synchronization plan.
Example
- All systems are to be operated synchronously at the Telecom network = simple private network;
- Private network with connection to one point and backup by GPS
- = Larger network with large amounts of internal traffic;
- Network with connections to various carriers and/or Telecom;
- Network is to become a carrier network.
First, create a topological network plan. The clock hierarchy plan is
derived from the network topology plan, which must contain all route
information, e.g. distances, line types, transmission equipment. Then
the network synchronization plan can be created.
Transmission equipment and multiplexers must be included into the
network synchronization plan.
When creating a network synchronization plan the number of clock hierarchy
levels is important since they must be limited for the network to remain
synchronous in all operating and error situations.