Relative synchronization system for a telephone network

摘要

A DS3 level access, monitor and test system for a telephone network. The system provides selective, and hitless, bit overwrite in any of the embedded DS1, DS0 and subrate channels in a DS3 signal. Multiple DS0 and subrate channels can be tested via the asynchronous time slot interchange in conjunction with the recombiner of the present invention. The present invention further includes a lookahead reframer for framing to the DS3 signal. The present invention also includes a facilities data link (FDL) handler for capturing the FDL channel data in every DS1 channel in a DS3 signal. A high speed bit-for-bit compare is interfaced to a protect path to provide 1:1 fault protection in the system of the present invention. Full time performance monitoring on DS1 and DS3 signals is performed by a shared resource. The system of the present invention provides an integrated approach to synchronization measurement and relative synchronization, and also provides alarm correlation and hierarchical event filtering.