1. 1 SDH 구조에서 에러와 알람의 원인 및 위치 Abbreviation SDH Old Abbr. Located in Byte Detection CriteriaMeaningITU-T Rec. LOSNO-SIGLoss of signalG.958 TSEBIT ERRORTest sequence error (bit error) LSSNO-PATTLoss of sequence synchronization R E G E N E R A T O R S E C T I O N OOFA1, A2A1,A2 errored for >= 625 usOut of frameG.783 LOFA1, A2if OOF >= 3msLoss of frameG.783 B1 (8 bits)B1contains all bits of frame behind scrambler B1 errors / block errors (regenerator bit error monitor) G.783 RS-TIMJ0online detectionTrace Identifier MismatchG.783 M U L T I P L E X S E C T ION B2 (24 bits)B2all bits of frame excluding RSOH before scrambler B2 errors / block errors (section bit error monitor) G.783 MS-REIM1Bits 1 to 8 contain number of detected anomalies B2 Mux section remote error indication : G.707 MS-AIS K2TX: all bits of frame except RSOH= 1 RX: K2-bits 6,7,8= 111 Multiplex section AISG.783 MS-RDIMS-FERFK2Bits 6,7,8 = 110Mux section remote defect indication G.783

2. 2 A D M I N I S T R A T I V E U N I T AU-LOPH1,H28...10 times NDF enable or 8...10 invalid pointers Loss of AU pointer (AU-3 or AU-4)G.783 AU-AIS AU incl H1,H2,H3 TX: all bits of AU.3/4 = 1 RX: H1, H2 =1 Administrative Unit AISG.783 AU-PJEH1, H2Pointer increment, decrementPointer Justification EventG.783 H O - P A T H B3 (8 bits)B3all bits VC3/4 including POHB3 errors / block errorsG.783 HP-REIHP-FEBEG1Bits 1,2,3,4 contain number of detected anomalies B3 HO path remote error indication :G.707 HP-RDIHP-FERFG1Bits 5,6,7 = 100 (bit 8 unused)HO path remote defect indication (VC3,4) G.783 HP-RDI-EP G1Bits 5,6,7 = 010 (bit 8 unused)HO path Enhanced RDI Payload Defect G.783 HP-RDI-ES G1Bits 5,6,7 = 101 (bit 8 unused)HO path Enhanced RDI Server Defect G.783 HP-RDI-EC G1Bits 5,6,7 = 110 (bit 8 unused)HO path Enhanced RDI Connectivity Defect G.783 HP TIMJ1Sequence online detectionHO path trace identifier mismatch (15bytes with CRC-byte or 64bytes) G.783 HP-PLM C2bit combination due to correspondent mapping structure HO path payload label mismatchG.783 HP-UNEQC2= 00HO path unequipped VC indication (VC3/4) G.783

3. 3 T R I B U T A R Y U N I T TU-LOPV1, V28...10 times NDF enable or 8...10 invalid pointers Loss of TU pointerG.783 TU-AISTU incl. V1 to V4 TX: All bits of TU = 1 RX: V1,V2 = 1 Tributary Unit AISG.783 TU-LOMH4Bits 7,8 not = 00, 01, 10, 11 sequenceLoss of TU multiframeG.783 L O - P A T H BIP-2V5VC 11,12,2 : V5-bits 7,6 contain all bits VC incl. POH BIP-2 errors / block errorsG.783 LP-REILP-FEBEG1 / V5VC 3 : G1-Bits 1,2,3,4 = number of detected B3 errors VC 11,12,2 : V5-bit 3 = 1 if BIP2 >= 1 error per frame LO path remote error indication G.707 LP-RDILP-FERFG1 / V5VC 3 : G1-bits 5,6,7 = 100 VC 11,12,2 : V5-bit 8 = 1 LO path remote defect indication G.783 LP-RDI-EP G1 / V5 / K4VC 3 : G1-bits 5,6,7 = 010 VC 11,12,2 : V5-bit 8 = 0 K4-bits 5,6,7 = 010 LO path Enhanced RDI Payload Defect G.707 LP-RDI-ES G1 / V5 / K4VC 3 : G1-bits 5,6,7 = 101 VC 11,12,2 : V5-bit 8 = 1 K4-bits 5,6,7 = 101 LO path Enhanced RDI Server Defect G.707 LP-RDI-EC G1 / V5 / K4VC 3 : G1-bits 5,6,7 = 110 VC 11,12,2 : V5-bit 8 = 1 K4-bits 5,6,7 = 110 LO path Enhanced RDI Connectivity Defect G.707 LP-RFIV5Bit 4 = 1LO path remote failure indication G.707 LP-TIMJ2Sequence online detectionLO path trace identifier mismatch G.783 LP-PLM C2 / V5bit combination due to correspondent mapping structure LO path payload label mismatch G.783 LP-UNEQC2 / V5VC3 : C2 = 00 VC11,12,2 : V5-bits 5,6,7 = 0 LO path unequipped VC indication G.783

4. 4 Data Com D8 Data Com D4 Data Com D7 Data Com D10 Data Com D5 Data Com D11 Data Com D6 Data Com D9 Data Com D12 APS K2 APS K1 Data Com D1 Data Com D3 Data Com D2 Section Overhead Path Trace J1 BIP-8 B3 Signal Label C2 Path Status G1 User Channel F2 Multiframe Indicator H4 User Channel F3 APS K3 Tandem N1 Framing A1 BIP-8 B1 Pointer H1 BIP-8 B2 Orderwire E1 Pointer H2 RS Trace J0 User Channel F1 Pointer H3 HO Path Overhead R-Section Overhead M-Section Overhead Framing A2 AU pointer SDH 오버헤드