A synchronization system in accordance with the principles of the invention includes
a central synchronizing management unit, at least one synchronization distribution
unit, and at least one network element. Each synchronization distribution unit
receives synchronization and management information from the central synchronization
management unit. This information may be transmitted directly from the central
synchronization management unit, or it may be transmitted though another synchronization
distribution unit in a group of a daisy-chained synchronization distribution units.
The daisy-chained arrangement employs both active and passive optical paths. The
central synchronizing management unit may query any synchronization distribution
unit within the system to obtain performance statistics. Additionally, the central
synchronizing management unit may detect faults within the system by setting performance
monitoring thresholds and interrogating a synchronization distribution unit to
determine whether a threshold has been exceeded. The synchronization distribution
units are physically located in close proximity to the network elements they serve.
Additionally, the management and synchronization information exchanged between
the central synchronization unit and a synchronization distribution unit is carried
over a bidirectional optical link.
