About for PDH
notifications
for PDH describes the failures diagnosed for each low-order element in the SDH network. for PDH cross-correlates with for SONET/SDH to calculate which root-cause problems are causing symptomatic events and creates notifications for the problem origin. The uses the relationships
in the topology to calculate the impact that a root-cause problem in one element has on the elements and services that are connected to, or depend on it.
When the receives alarms that relate to connections to elements that it does not manage, the performs special analysis to determine if a problem has occurred in the connected
network. This is described in “Diagnosis of external failure” on page 80.
Protection Schemes on page 95 provides For detailed information about the protection
schemes supported by the Optical Transport Manager.