SoftIP IP Group of Alphawave IP
SoftIP IP Group of Alphawave IP

SONET/SDH : OC12/4xOC3 | STM-4/4xSTM-1 Framer


The SONET/SDH  OC12/4xOC3 & STM-4/4xSTM-1 Framer core implements the STS-12/4xSTS-3 and STM-4/4xSTM-1 layer function of Telcordia GR-253-CORE/ITU-T G.707, supporting data rate at 622M/s.

The Core is configurable to work with OC12 signal or 4xOC3 signals.

Figure 1 Block level diagram of STS12

In the source direction, the payload is loaded by the SPE handler which sends out data request to the source client. The SPE handler wraps the payloads into a SPE envelope. The SPE envelope is then framed with STS or STM frame structure by the Source Frame Generator. The TOH generator provides all transport overhead information (TOH) to the Source Frame Generator. The TOH can be programmed by software or altered by External TOH Insert Port.

In the sink direction, the Sink Framer delineates the STS or STM frame structure and extracts the TOH and sends the TOH to TOH processor for alarm and OAM processing. All TOH bytes are made available to the External TOH Extract Port. The SPE envelope is sent to the Payload Extractor for payload extraction.


Source Direction

  • Support software programmable TOH bytes per bit with bit mask
  • Support external TOH insertion on all TOH bytes per bit with bit mask
  • Support software programmable on all POH bytes with bit mask
  • Support optional frame scrambling
  • Support B1/B2/B3 calculation and corruption via software mask or external TOH insert
  • Support software programmable AIS-P and AIS-L generation
  • Support J0 and J1 trace messages
  • Support extended 64-byte J1 trace messages
  • Support statistic frame counts

Sink Direction

  • Provide software programmable FAS (A1/A2) pattern for framer
  • Provide full TOH extraction to software
  • Provide full TOH extraction to external TOH extractor
  • Provide full POH extraction to software
  • Provide alarm detection and B1/B2/B3 error counts, Frame count, pointer negative/positive stuff counts
  • Provide consistency checked K1, K2 & S1 bytes
  • Provide inconsistency alarm on K1, K2 & S1 bytes
  • Provide detection on J0 and J1 trace mismatches

Supported alarm detection and interruption

  • LOS
  • AIS-L
  • RDI-L
  • AIS-P
  • LOP-P
  • PLM-P
  • LCD-P
  • Far end – AIS-P
  • Far end – LOP-P
  • Far end – PLM-P
  • Far end – LCD-P
  • J0 & J1 mismatches
  • K1, K2 & S1 consistencies
  • K1, K2 & S1 inconsistencies
  • Pointer increment & decrement events
  • Pointer NDF event
  • B1, B2 & B3 error alarms


Standard Compliance

  • ITU-T REC-G.707/Y.1332-01/2007
  • ITU-T G.783 (03/2006)
  • Telcordia GR-253-CORE