1. Pointer H1 Pointer H2 Pointer H3 BIP-8 B2 APS K1 APS K2 DCC D4 DCC D5 DCC D6 DCC D7 DCC D8 DCC D9 DCC D10 DCC D11 DCC D12 Sync S1/Z1 FEBE M0/M1/Z2 OW E2 Transport overhead 125 microsec. 9 rows 90 bytes 3 bytes Transport Overhead STS-1 Envelope Capacity Framing A1 Framing A2 Section Trace J0 BIP-8 B1 OW E1 User F1 DCC D1 DCC D2 DCC D3 Line Overhead Section Overhead 29

2. STS-1 SPE path overhead STS-1 Envelope Capacity 9 rows 90 bytes 3 bytes Transport Overhead STS Path Overhead Trace J1 BIP-8 B3 Label C2 Status G1 User F2 Multiframe H4 Growth Z3 Growth Z4 TCM Z5 Payload Capacity Synchronous Payload Envelope 30

3. Framing bytes (A1, A2) 1 1 1 1 0 1 1 0 0 0 1 0 1 0 0 0 A1 ByteA2 Byte 1234567812345678 Hex: F628 31

4. Scrambling Envelope Capacity 125 microsec. Transport Overhead Scrambler polynomial = 1 + X 6 + X 7 Scrambler reset to 11111111 Not scrambled Scrambled 32

5. Section trace (J0) Trace ID Value ID=2 ID=3 ID=4 ID=5 J0 Byte 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 33

6. Path trace (J1) Vancouver Toronto DS3 Path trace code assigned to indicate physical location of path source Equipment provisioned to monitor path trace code = Vancouver CRLF 64 character ASCII string STS-1 framenn+1n+2n+63 J1 bytes Common Language Location Identifier (CLLI) Recommended Use: 34

7. Section BIP-8 (B1) Even parity calculated over all bit 1s from entire STS-N frame Even parity calculated over all bit 8s from entire STS-N frame B1 Byte 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 35

8. Line BIP-8 (B2) Even parity calculated over all bit 1s from entire STS-1 frame excluding section overhead Even parity calculated over all bit 8s from entire STS-1 frame excluding section overhead B2 Byte 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 36

9. Line remote error indication (M0/M1) Example: 2 out of 8 B2 (Line BIP-8) parity bits detected as wrong in frame n Line REI sent with binary value 2 in next outgoing frame 4 bit binary value for OC-1 interfaces (M0) M0/M1 Byte 8 bit binary value for OC-N interfaces (M1) 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 37

10. Path BIP-8 (B3) Even parity calculated over all bit 1s from entire SPE frame Even parity calculated over all bit 8s from entire SPE frame B3 Byte 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 38

11. Path status (G1) G1 Byte Path REIRDIUnused REI = Remote Error Indication RDI = Remote Defect Indication 0 X X No defects 0 0 1 No defects 0 1 0 Payload defects (payload label mismatch, ATM loss of cell delineation) 1 1 0 Connectivity defects (path trace mismatch, unequipped) 1 0 1 Server defects (path AIS, loss of pointer) NOTE: Exceptions to handle backwards compatibility are documented in GR-253. 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 39

12. Line RDI K2 Byte Channel # 111 Line AIS 110 Line RDI 101 Bidirectional APS 100 Unidirectional APS 0 1+1 Mode 1 1:N Mode 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 40

13. Section orderwire (E1) Line Terminal Regenerator Line Terminal E1 Byte 41

14. Line orderwire (E2) Line Terminal Regenerator Line Terminal E2 Byte 42

15. Section user channel (F1) Line Terminal Regenerator Line Terminal F1 Byte Alarm Monitor Monitored Element 43

16. Path user channel (F2) Vancouver Toronto DS3 User Info F2 Byte 44

17. SONET data communications channels (D1-D3, D4-D12) OS = Operations System NE = Network Element NE D1-3 Bytes = Section Data Comm Channel (192 kbit/s) D4-12 Bytes = Line Data Comm Channel (576 kbit/s) OS NE External Data Network NE Gateway NE 45

18. Synchronization status messaging (S1) Building Integrated Timing Supply S1= Stratum 1 traceableS1= Stratum 3 traceableS1= Stratum 1 traceable S1 = Don’t Use BITS S1 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 0 0 0 0 Synchronized - traceability unknown 0 0 0 1 Stratum 1 traceable 0 1 1 1 Stratum 2 traceable 1 0 1 0 Stratum 3 traceable 1 1 0 0 20ppm clock traceable 1 1 1 0 Reserved for network synchronization 1 1 1 1 Don’t use for synchronization 47

19. Path signal label (C2) Hex ValuePayload 00 01 02 04 12 13 14 15 E1-FC Unequipped Equipped - Nonspecific payload Virtual Tributaries DS3 139.264Mb/s ATM DQDB FDDI Payload Defect Indicator (PDI) C2 Byte 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 48

20. Tandem connection monitoring Photonic Convert STS-N signal to optical pulses Section Framing and scrambling Add section overhead Line Multiplex SPEs Add line overhead Automatic protection STS Path Map payloads into STS SPE Add path overhead SONET Network Element STS Synchronous Payload Envelope STS-N with Line Overhead Light pulses STS-N with Line and Section Overhead Payloads (DS3, video) Payloads (DS1, DS2) VT Path Map payloads into VT SPE Add path OH VT Synchronous Payload Envelope Optional Tandem Connection Performance monitoring over path segments STS Synchronous Payload Envelope 49

21. Tandem connection monitoring STS Path Line Section Photonic STS Path DS3 Section Line Tandem Connection STS Path Path Terminating Equipment (PTE) Tandem Connection Terminating Equipment (TCTE) Line Terminating Equipment (LTE) Tandem Connection Terminating Equipment (TCTE) Path Terminating Equipment (PTE) TC Line Section Photonic Line Section Photonic STS Path TC Line Section Photonic Line Section Photonic 50

22. TCM byte (Z5) Z5 Byte IECData Link IEC - Incoming Error Count PTETCTE PTE DS3 IEC and Data Link Tandem Connection Monitor OC-12 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 OC-48OC-12 51

23. STS-1 payload pointer offset STS Pointer Frame N STS Pointer Frame N + 1 STS-1 SPE 125 µs 250 µs 1 40 41 87 90 bytes 63

24. STS payload pointer (H1, H2) I - Increment Bits D - Decrement Bits NDF Not Set = 0110 NDF Set = 1001 Concatenation Flag H1H2 0110XXIDIDIDIDID 1234567812345678 Not Used 1001001111111111 New Data Flag Pointer Offset 70

25. Multiframe indicator (H4) 00 H4 V4 Bytes 01 H4 V1 Bytes 10 H4 V2 Bytes 11 H4 V3 Bytes 00 H4 V4 Bytes 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 H4 Byte VT SubFrame Counter X X X 88

26. Single-ended performance monitoring DS3 Path Terminal Line Terminal Path Terminal DS3 Degraded Section BIP-8 (B1) B1 errors detected B1 Line BIP-8 (B2) B2 errors detected B2 Line REI (M0/M1) Far-end line errors counted M0/M1 Path BIP-8 (B3) B3 errors detected Path REI (G1 bits 1-4) Far-end path errors counted Regen Time Flow 99

27. Maintenance signaling DS1 VT/STS Path Terminal Line Terminal STS Path Terminal DS1 Regen LOS detected Line AIS STS Path AIS (H1/H2) STS Path AIS detected STS Path RDI (G1) STS Path RDI detected Line AIS detected (K2) Line RDI (K2) Line RDI detected VT/STS Path Terminal VT AIS (V1/V2) DS3 DS3 AIS VT Path AIS detected VT Path RDI detected VT Path RDI (V5) (The remaining signaling only occurs if the Line Terminal cannot restore the traffic with a protection switch) Time Flow VT/STS Path Terminal STS Path AIS (H1/H2) STS Path AIS detected DS1 DS1 AIS VT Path AIS detected DS1 AIS VT Path RDI (V5) STS Path RDI (G1) 100

28. Linear 1+1 Line Terminal Line Terminal Line Terminal Line Terminal Working Channel Protection Channel Regen 102

29. Linear 1:N Line Terminal Line Terminal Line Terminal Line Terminal Working Channel #1 Protection Channel Working Channel #2 Working Channel #N 103

30. APS bytes (K1, K2) - linear protection Switch Preemption Priority 1111 Lockout of Protection 1110 Forced Switch 1101 Signal Fail - High 1100 Signal Fail - Low 1011 Signal Degrade - High 1010 Signal Degrade - Low 1001 1000 Manual Switch 0111 0110 Wait-to-Restore 0101 0100 Exercisor 0011 0010 Reverse Request 0001 Do Not Revert 0000 No Request 12345678 K1 Byte Channel # 12345678 K2 Byte Channel #111 Line AIS 110 Line RDI 101 Bidirectional APS 100 Unidirectional APS 0 1+1 Mode 1 1:N Mode 104

31. 1:N APS signaling Line Terminal Line Terminal Line Terminal Line Terminal Working Channel #1 Protection Channel Working Channel #2 Working Channel #N Signal Fail detected on Chn 2 K1 = Signal Fail, Chn 2 K2 = Chn 1, 1:N, Bi K1 = Reverse Request, Chn 2 K2 = Chn 2, 1:N, Bi K1 = Signal Fail, Chn 2 K2 = Chn 2, 1:N, Bi Chn 2 bridged Chn 2 bridged & switched Time Flow 105

32. Unidirectional path switched rings Working Protection Ring Node 106

33. Unidirectional path switched rings Working Fiber Protection Fiber Ring Node Fiber Cut Path AIS 107

34. Bidirectional line switched rings Ring Node Clockwise Fiber Counter Clockwise Fiber 108

35. Bidirectional line switched rings Ring Node Fiber Cut Clockwise - Working CCW - Working CW - Prot. CCW - Prot. 109

36. APS bytes (K1, K2) - ring protection Switch Preemption Priority 1111 Lockout of Protection 1110 Forced Switch - Span 1101 Forced Switch - Ring 1100 Signal Fail - Span 1011 Signal Fail - Ring 1010 Signal Degrade - Protection 1001 Signal Degrade - Span 1000 Signal Degrade - Ring 0111 Manual Switch - Span 0110 Manual Switch - Ring 0101 Wait-to-Restore 0100 Exercisor - Span 0011 Exercisor - Ring 0010 Reverse Request - Span 0001 Reverse Request - Ring 0000 No Request 111 Line AIS 110 Line RDI 011 Extra Traffic 010 Bridged and Switched Status 001 Bridged Status 000 Idle K2 Byte Destination Node ID 12345678 K1 Byte 12345678 Source Node ID 0 Short Path Code 1 Long Path Code 110

37. Survivable ring interconnect Ring #1Ring #2 SEL Drop and Continue Path Selection Protection path may be carried on working channels or protection channels DS1, DS3, STS-N, OC-N 111

38. Payload defect indicator Ring #1Ring #2 SEL DCS DS3 STS-1 STS Payload Defect Indicator (PDI) triggers the selector in the event of the DS3 failure STS-1 112

39. ITU - SDH recommendations G.707 SDH bit rates, frame & multiplexing structure, mappings, and functions of overhead G.781 structure of recommendations on SDH equipment G.782 types and general characteristics of SDH equipment G.783 characteristics of SDH equipment functional blocks G.784 management of SDH equipment and networks G.803 SDH transport network architectures G.841 SDH network protection architectures G.842 interworking of SDH network protection architectures G.957 optical interface specifications for SDH systems G.958 interface specifications for SDH systems 114

40. ANSI standards ANSI T1.105 basic SONET format, overhead definitions ANSI T1.105.01 SONET automatic protection switching ANSI T1.105.02 SONET payload mappings ANSI T1.105.03 Jitter at (SONET) Network Interfaces ANSI T1.105.04 SONET Data Communications Channel Protocols and Architecture ANSI T1.105.05 Tandem Connection Monitoring ANSI T1.105.06 SONET physical layer specifications ANSI T1.105.07 Sub-STS-1 Interface Rates and Formats (VT1.5 and VT Group) ANSI T1.105.09 SONET Timing and Synchronization ANSI T1.106 Original version of ANSI T1.105.06 ANSI T1.117 Electrical physical layer specifications including STS-1 and STS-3 115

41. Bellcore standards GR-499 SONET Transport System Generic Requirements GR-253 SONET Common Generic Criteria GR-1377 OC-192 Criteria GR-1230 Bidirectional Line Switched Rings (BLSR) GR-1400 Unidirectional Path Switched Rings (UPSR) 116

42. ETSI standards ETS 300 147 SDH multiplexing structure ETS 300 232/A1 Optical interfaces for SDH ETS 300 417-1-1 SDH equipment; Generic processes and performance ETS 300 417-2-1 SDH and PDH physical section layer functions ETS 300 417-4-1 SDH path layer functions ETS 300 462-5 Generic requirements for synchronization of SDH ETS 300 746 SDH network protection ETS 300 484 SDH information model ETR 114 architecture of SDH transport networks 117