The DOHP155T-320 is a monolithic integrated circuit that processes the section overhead of STM-1 streams at up to 155.52 Mb/s and implements payload alignment and path termination for VC-4 payload.
The DOHP155T-320 receives dual SDH STM-1 frames via a bit serial interface and it processes dual regenerator section overhead and APS bytes (K1, K2).It supports 1+1 MSP protection. Only the “multiplexer section” overhead on the selected STM-1 data stream is processed. On the outgoing STM-1 stream, the STM-1 data excluded REG Overhead, K1/K2 and B2 are duplicated. It performs framing (A1, A2), de-scrambling, detects alarm conditions, and monitors regenerator section and multiplex section bit interleaved parity (B1, B2), accumulating error counts at each level for performance monitoring purposes. Multiplex section far end block error (REI) indications (M1) are also monitored. A 1, 16 bytes section trace (J0) sequence may be processed.
The DOHP155T-320 provides external serial access to all section overhead bytes, which are extracted and serialized on lower rate interfaces, allowing additional external processing of all section overhead.
The DOHP155T-320 transmits SDH STM-1 frames, via a bit-serial interface, and formats regenerator section and multiplex section overhead appropriately. It performs framing pattern insertion (A1, A2), scrambling, alarm signal insertion, and creates regenerator section and multiplex section bit interleaved parity (B1, B2) as required to allow performance monitoring at the far end.Multiplex section far end block error (REI)