CPE (COMMUNICATION PROTOCOL ERROR) ALARM IN NOKIA DXC)

Earlier the standard was known as SONET (Synchronous Optical Networking). Later, ANSI limited SONET standards for use in North America only and SDH was defined by ETSI (a subset of ITU-T) for the use in the rest of the world. [1] PDH provided asynchronous digital hierarchy therefore introduction of SDH in 1988 lead to solution of timing problem of PDH systems. When asynchronous PDH signals are fed to the SDH multiplexer, multiple VCs (Virtual Containers) which are timed by different clocks combines into one STN-N signal that the local equipment clock times