OTN NEWBIES 1 FOREWORD According to the ITU-T Recommendation G.709, an Optical Transport Network (OTN) is composed of a set of optical network elements connected by optical fiber links. The network provides functionality of transport, multiplexing, routing, management, supervision, and survivability of optical channels carrying client signals. This architecture can be seen as a combination of the advantages of SDH/SONET technology with the flexibility of DWDM. Using OTN, the OAM&P functionality of SDH/SONET is applied to DWDM optical networks. Compared to SDH/SONET, OTN has the following advantages: • Stronger error correction mechanisms • More levels of tandem connection monitoring • Transparent transport of client signals • Switching scalabilityIntroduction Page2 ABOUT THIS COURSE This course is based on the following ITU-T recommendations: ITU-T G.709 ITU-T G.805 ITU-T G.806 ITU-T G.798 Page3 LEARNING GUIDE Just little Basics 4 CONTENTS 1. OTN Introduction 2. Typical OTN Scenarios Page5 CONTENTS 1. OTN Introduction 1.1 OTH 1.2 OTN Port Structure 1.3 Multiplexing/Mapping Principles and Bit Rates 1.4 Overhead Description 1.5 Maintenance Signals and Functions of Different Layers 1.6 Alarms and Performance Events Page6 OTN Optical transport network (OTN) An OTN network is composed of a set of optical NEs connected by optical fiber links. These NEs are able to provide functions such as transport, multiplexing, routing, management, supervision, and protection (survivability) of client signals, according to the requirements specified in REC. G.872. Page7 FEATURES OF OTN Compared with SDH and SONET networks, an OTN network has the following features: Ultra capacity with high accuracy, T-bit/second per fiber over DWDM lines Service transparency for client signals Asynchronous mapping, powerful FEC function, simplified network design, and reduced costs Compared with traditional WDM networks, an OTN network has the following features: Enhanced OAM and networking capabilities for all services Dynamic electrical/optical-layer grooming Page8 OTN STANDARD SYSTEM OTN Equipment G.874 Management features of NEs on an OTN network management G.874.1 OTN network: Protocol-neutral management information model for the network element Jitter and G.8251 Jitter and shift control on an OTN network performance G.8201 Bit error performance parameters and specifications on international channels of multiple carriers on an OTN network Network G.873.1 Linear protection on an OTN network protection G.873.2 Ring protection on an OTN network Equipment functions and features G.798 Features of function blocks of equipment on an OTN network G.806 Transport network equipment features: description methods and general functions G.709 Ports on an OTN network G.7041 Generic frame protocol (GFP) G.7042 Link capacity adjustment scheme (LCAS) for virtual concatenation signals G.959.1 Physical-layer ports on an OTN network G.693 Optical ports for intra-office systems G.664 Optical security rule and requirements in an optical transport system G.872 OTN network structure G.8080 ASON network structure Structure and mapping Physical-layer features Structure 9 OTN NETWORK LAYERS AND PORT STRUCTURE OPUk: optical channel payload unit-k ODUk: optical channel data unit-k OTUk: completely standardized optical channel transport unit-k OTUkV: functionally standardized Optical channel transport unit-k OCh: optical channel with full functionality OChr: optical channel with reduced functionality OMS: optical multiplex section OTS: optical transmission section OPS: optical physical section OTM: optical transport module IP/MPLS ATM Ethernet STM-N OPUk ODUk (ODUkP and ODUkT) OTUk OTUkV OTUk OTUkV OCh OChr OMSn OTSn OPSn OTM-n.m OTM-0.m OTM-nr.m Page10 OTM-N.M CONTAINMENT RELATIONSHIPS Client signal ODUk OTUk[V] OH OH OMU-n.m OTM-n.m OCCo OCCo Non-associated OH Common management OCCo OH OCG-n.m OPUk ODUk OCh OChOH ln OPUk payload FEC OCh payload OCCp OCCp OCCp OTM-n. m OH OPUk l2 l1 l OSC OTM overhead signal (OOS) OMSn OH OTSn OH OOS “n” represents the maximum number of wavelengths that can be supported at the lowest bit rate supported by the wavelengths. “m” equals 1, 2, 3, 12, 23, or 123. OTS_OH, OMS_OH, OCh_OH and COMMS OH information fields are contained in the OOS. The optical supervisory channel (OSC) is used to transmit OOSs. Page11 OTM-NR.M CONTAINMENT RELATIONSHIPS Client signal ODUk OTUk[V] OH OPUk payload OH OH OPUk ODUk OChr OCG-nr.m OTM-16r.m OPUk l 16 FEC l l 2 1 OCh payload OCCp OCCp OCCp OTM-nr.m Fixed channel spacing, irrelevant to the signal rate 1 < n ≤ 16; m = 1, 2, 3, 12, 23, or 123 Without optical supervisory channels Page12 OTM-0.M CONTAINMENT RELATIONSHIPS OPUk ODUk OTUk[V] OH OH OChr OTM-0.m OH OTM-0.m Client signal OPUk payload OPUk ODUk FEC OCh payload OPS0 The OTM 0.m supports a non-colored optical channel on a single optical span with 3R regeneration at each end. m = 1, 2, or 3 Without optical supervisory channels Page13 OTN PORTS Network Operator B USER A OTM NNI IaDI-IrVI OTM UNI Vendors X Vendors Y Inter-domain interface (IrDI) Intra-domain interface (IaDI) OTM NNI IaDI-IaVI User to network interface (UNI) Network node interface (NNI) OTM NNI IaDI-IaVI OTM NNI IrDI Network Operator C Between equipment provided by different vendors (IrVI) Within subnet of one vendor (IaVI) The completely standardized OTUk is used at OTM IrDIs and OTM IaDIs. The partly standardized OTUk is used at OTM IaDIs. Page14 CONTENTS 1. OTN introduction 1.1 Optical transport hierarchy 1.2 OTN interface structure 1.3 Multiplexing/mapping principles and bit rates 1.4 Overhead description 1.5 Maintenance signals and function for different layers 1.6 Alarm and performance events Page15 OTN MULTIPLEXING AND MAPPING STRUCTURE OTM-0.m 1 ≤ i+j+k ≤ n OTM-nr.m OCCr i OCG-nr.m j OCCr 1 OChr 1 OChr k OCCr 1 OChr 1 1 OTU3[V] 1 i 1 ≤ i+j+k ≤ n OTM-n.m OCG-n.m j OCC OCC k 1 OCC OSC 1 1 1 1 OCh OCh OCh ODU3 1 Client signal OPU3 1 1 1 OTU1[V] 1 ODTUG3 16 4 ODU2 1 Client signal OPU2 1 ODTUG2 4 1 ODU1 1 OPU1 1 Multiplexing OOS OTS, OMS, OCh, COMMS Mapping Page16 Client signal OTU2[V] 1 OTN Multiplexing and Mapping Structure 17 OTN Multiplexing and Mapping Structure 18 OTN Service Bearing Capability (LO ODU) Client service rate LO ODU New LO ODU signals 10.3G ODU2e 104G ODU4 ODUflex OPU3 40.149G OPUflex 10.312G 9.995G OPU2 OPU2e OPUflex 2.488G 1.238G OPUflex(GFP) 1.25G ODU0 OPUflex OPU4 104.134G OPU1 OPU0 LO OPU 19 OTN LINE BEARING CAPABILITY (HO ODU) LO ODU rate ODU4 New HO ODU signals OPU4/21 104G ODU4 Signals with extended OPU3/21 (ODU0, ODU1, ODU2, ODU2e, ODUflex) OPU3e2/21 (ODU0, ODU1, ODU2, ODU2e, ODU3, ODU3e2, ODUflex) 41.7GG ODU3e2 (G.sup43) – 10G ODU2 – 40G ODU3 ODU2e ODU2 ODU1 (ODU0) OPU1 ODU0 ODUflex (ODU1) OPU2/20 (ODU0, ODU1, ODUflex) OPU2/21 (ODU1, ODU2) OPU3/20 (ODU0, ODU1, ODU2, ODU2e, ODUflex) capabilities ODUflex(GFP) ODUflex ODUflex 2.5G ODU1 ODU3e2 ODU3 HO OPU 20 OTUK FRAME RATE OTUk rate = 255/(239 - k) x STM-N frame rate OTU Type OTU Nominal Bit Rate OTU1 255/238 x 2488320 kbit/s OTU2 255/237 x 9953280 kbit/s OTU3 255/236 x 39813120 kbit/s OTU4 255/227 x 99532800 kbit/s OTU Bit Rate Tolerance 20 ppm Note 1: The nominal OTUk rates are approximately 2666057.143 kbit/s (OTU1), 10709225.316 kbit/s (OTU2), 43018413.559 kbit/s (OTU3) and 111809 973.568 kbit/s (OTU4). Note 2: OTU0, OTU2e and OTUflex are not specified in this recommendation. ODU0 signals are transported over ODU1, ODU2, ODU3 or ODU4 signals, ODU2e signals are transported over ODU3 and ODU4 signals, and ODUflex signals are transported over ODU2, ODU3 and ODU4 signals. ODUK FRAME RATE ODUk rate = 239/(239 - k) x STM-N frame rate ODU Type ODU Nominal Bit Rate ODU0 1244160 kbit/s ODU1 239/238 x 2488320 kbit/s ODU2 239/237 x 9953280 kbit/s ODU3 239/236 x 39813120 kbit/s ODU4 239/227 x 99532800 kbit/s ODU2e 239/237 x 10312500 kbit/s ODUflex for CBR client signals 239/238 x Client signal bit rate ODUflex for GFP-F mapped client signals Pre-set bit rate ODU Bit Rate Tolerance 20 ppm 100 ppm Client signal bit rate tolerance, with a maximum of 100 ppm 20 ppm OPUK FRAME RATE OPUk payload rate = 238/(239 - k) x STM-N frame rate OPU Type OPU Payload Nominal Bit Rate OPU0 238/239 x 1244160 kbit/s OPU1 2488320 kbit/s OPU2 238/237 x 9953280 kbit/s OPU3 238/236 x 39813120 kbit/s OPU4 238/227 x 99532800 kbit/s OPU2e 238/237 x 10312500 kbit/s OPUflex for CBR client signals Client signal bit rate OPUflex for GFP-F mapped client signals 238/239 x ODUflex signal rate OPU1-Xv X x 2 488 320 kbit/s OPU2-Xv X x 238/237 x 9953280 kbit/s OPU Payload Bit Rate Tolerance 20 ppm 100 ppm Client signal bit rate tolerance, with a maximum of 100 ppm 20 ppm 20 ppm ODUK (TDM) Low-rate ODUk signals are multiplexed into highrate ODUk signals using time-division multiplexing: A maximum of four ODU1 signals are multiplexed into one ODU2 signal using time-division multiplexing. Hybrid j (j 4) ODU2 and 16-4j ODU1 signals are multiplexed into one ODU3 signal using time-division multiplexing. Multiple LO ODUi[j] signals at different levels are multiplexed into one HO ODUk signal. Page24 ODU1 MULTIPLEXED INTO ODU2 ODTU12: optical channel data tributary unit 1 into 2 ODTUG2: optical channel data tributary unit group 2 JOH: justification overhead ODU1 OH ODTU12 JOH ODTU12 JOH ODTU12 JOH ODU1 payload ODU1 ODTU12 ODU1 ODU1 ODU1 ODTUG2 ODTUG2 OPU2 OH ODU2 OH OPU2 payload ODU2 payload OPU2 ODU2 Page25 ODU1 MULTIPLEXED INTO ODU2 ODU1 OPU1 OH Alignment ODU1OH Client-layer signal (STM-16, ATM, or GFP) Alignment OTU2 OH OTU2 ODU2 OH ODU1 OH ODU1 OH ODU1 OH ODU1 OH Alignment ODU1 OH ODU1 OH ODU1 OH ODU1 OH OPU1 OH ODU2 OH OPU1 OH OPU1 OH OPU1 OH Alignment OPU1 OH OPU1 OH OPU1 OH ODU2 OPU2 OH x4 OPU1 OH ODU1 floats in one quarter of the OPU2 payload area. An ODU1 frame travels cross multiple ODU2 frame boundaries. OPU2 OH Client Layer Signal Client(for Layer SignalSTM-16) example, Client Layer SignalSTM-16) (for example, Client-layer signal (for example, STM-16) (STM-16, ATM, or GFP) Client Layer Signal Client(for Layer SignalSTM-16) example, Client(for Layer SignalSTM-16) example, Client-layer signal OPU2 Payload (for example, STM-16) (STM-16, ATM, or GFP) OTU2 FEC Page26 ODU1 AND ODU2 MULTIPLEXED INTO ODU3 ODTU23: optical channel data tributary unit 2 into 3 ODTU13: optical channel data tributary unit 1 into 3 ODU2 OH ODTU23 JOH ODTU13 JOH ODU2 payload ODTU23 ODU2 ODTU13 ODTU23 JOH JOH ODTU23 JOH ODU1 ODU1 payload OH ODU2 ODU2 ODTU13 JOH ODU2 ODTU13 ODU1 ODU1 ODU1 ODU1 ODTUG3 ODTUG3 OPU3 OH ODU3 OH OPU3 payload ODU3 payload OPU3 ODU3 Page27 GMP Mapping 0 Payload Area Pserver OH client data stuff Pserver? enable client data indication = read/write enable memory payload area frame start clock Cm(t) server frame or multi-frame GMP can automatically adapt CBR services to an OTN container. It is the key technology for an OTN network to bear multiple services. Service rate information transmitted in overheads Sigma-delta algorithm M byte bit width Separation of data and clocks 28 ODUflex TSi TSj Services with a fixed bit rate BMP OH Client signals Packet services Client services GMP OH ODUflex GFP TSi TSj GMP OH OH ODUflex Map CBR services to ODUflex services using synchronized packet encapsulation. Map packet services to ODUflex services using GFP. Map ODUflex services to HO OPUk services using GMP. 29 CONTENTS 1. OTN introduction 1.1 Optical transport hierarchy 1.2 OTN interface structure 1.3 Multiplexing/mapping principles and bit rates 1.4 Overhead description 1.5 Maintenance signals and function for different layers 1.6 Alarm and performance events Page30 OOS n FDI-P TTI 1 BDI-O FDI-O BDI-P BDI-P FDI-P PMI PMI OCh BDI-O OMSn OTSn Non-associated overhead FDI-O 2 3 OOS functions subject to standardization. Bit rate and format are not standardized. OCI General management communication TTI: trail trace identifier PMI: payload missing indication OCI: open connection indication BDI-O: backward defect indication - overhead BDI-P: backward defect indication - payload FDI-O: forward defect indication - overhead FDI-P: forward defect indication - payload Page31 OPTICAL-LAYER FUNCTION OTSn OH TTI MI_TxTI BDI-O RI_BDI-O BDI-P OTSn Payload PMI dLOS_P RI_BDI-P aPMI OA, DCM Payload and OH combined together APR control The OTS source function is used as an example. Page32 Alignment 2 3 4 ODUk OH Client signal mapped in OPUk payload OPU k payload 4080 3825 3824 14 15 16 17 OTUk OH OPUk OH 1 7 8 1 OTN FRAME FORMATS (K = 1, 2, OR 3) OTUK FEC Client signal OPUk - optical channel payload unit ODUk - Optical Channel Data Unit OTUk - Optical Channel Transport Unit K: 1 - 2.5G 2 - 10G 3 - 40G Alignment Page33 33 OTN ELECTRICAL OVERHEAD OVERVIEW 1 2 4 5 6 FAS 1 2 RES 3 TCM3 GCC1 4 3 ODUk OH TCM ACT 7 9 TCM6 10 SM MFAS TCM2 GCC2 8 11 12 GCC0 TCM5 TCM4 TCM1 PM APS/PCC 13 14 15 16 RES JC FTFL RES JC RES EXP RES RES 17 JC PSI NJO Alignment OH TCMACT: tandem connection monitoring FAS: frame alignment signal activation/deactivation control channel MFAS: multiframe alignment signal TCMi: tandem connection monitoring i OPUk OH FTFL: fault type and fault location reporting PSI: payload structure identifier channel JC: justification control PM: path monitoring NJO: negative justification opportunity EXP: experimental GCC1/2: general communication channel 1/2 OTUk OH APS/PCC: automatic protection switching SM: section monitoring coordination channel/protection GCC0: general communication channel 0 communication control channel RES: reserved for future international standardization Page34 FRAME ALIGNMENT SIGNAL 1 2 3 4 5 6 FAS 1 2 RES 3 TCM3 GCC1 4 Byte 1 7 8 9 MFAS TCM ACT SM TCM6 TCM1 APS/PCC Byte 2 11 12 GCC0 TCM5 TCM2 GCC2 10 TCM4 PM 13 14 RES 15 Byte 4 17 RES JC FTFL RES JC EXP RES JC RES Byte 3 16 PSI NJO Byte 5 Byte 6 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 OA1 OA1 OA1 OA2 OA2 OA2 Frame alignment signal (FAS) A six-byte OTUk-FAS signal is defined in row 1 and columns 1 to 6 of the OTUk overhead. OA1 is 0xF6 (1111 0110) and OA2 is 0x28 (0010 1000). Page35 MULTIFRAME ALIGNMENT SIGNAL 1 2 3 4 5 6 FAS 1 RES 3 TCM3 GCC1 4 8 TCM1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 1 1 0 0 1 1 0 0 1 1 0 0 0 1 0 1 .. .. .. PM 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO Multiframe alignment signal (MFAS) It is defined in row 1 and column 7. The value of the MFAS byte is increased by OTUk/ODUk frame and the MFAS byte provides a maximum of 256 MFAS sequence 0 0 0 0 0 TCM4 RES . . 0 0 0 0 0 12 GCC0 APS/PCC 1 2 3 4 5 6 7 8 0 0 0 0 0 11 TCM5 TCM2 GCC2 10 SM TCM6 MFAS OH byte 0 0 0 0 0 9 MFAS TCM ACT 2 7 multiframes. Individual OTUk/ODUk overhead signals may use this central multiframe to lock their 2, 4, 8, 16, or 32 multiframes to the main frame. Page36 OTUK SECTION MONITORING OVERHEAD 1 2 3 4 5 6 FAS 1 2 RES 3 TCM3 GCC2 2 TTI BIP-8 TCM1 BEI/BIAE 4 5 6 7 IAE 3 BDI SAPI 15 16 2 RES 63 GCC0 TCM4 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO Trail trace identifier (TTI) A one-byte overhead is defined to transport 64-byte TTI signals. 8 The 64-byte TTI signal should be aligned with the OTUk multiframe and transmitted four times per multiframe. Operator specified 12 RES DAPI 31 32 11 PM APS/PCC 3 1 10 TCM5 0 9 SM TCM6 TCM2 1 8 MFAS TCM ACT GCC1 4 7 TTI structure: 16-byte SAPI: source access point identifier 16-byte DAPI: destination access point identifier 32-byte operator specified information Page37 OTUK SECTION MONITORING OVERHEAD Bit interleaved parity-8 (BIP-8) For section monitoring and a one-byte error detection code signals are defined. This byte provides a bit interleaved parity-8 (BIP-8) code. OTUk BIP-8 is computed over bits in the OPUk (columns 15 to 3824) area of OTUk frame i, and inserted in the OTUk BIP-8 overhead location in OTUk frame i+2. 1 Frame i 14 3824 15 OPUk BIP8 Frame i+1 Frame i+2 Page38 OTUK SECTION MONITORING OVERHEAD 1 2 3 4 5 6 7 FAS 1 RES 3 TCM3 GCC2 TTI BIP-8 SAPI 2 3 BEI/BIAE 4 GCC0 TCM4 13 14 RES 15 16 RES JC FTFL RES JC EXP RES JC PSI NJO Backward error indication/backward incoming alignment error (BEI/BIAE) 5 6 7 8 RES A four-bit BEI and BIAE signal is defined. This signal is used to transmit in the upstream direction the count of interleaved-bit blocks and incoming alignment error (IAE) conditions. During an IAE condition the code "1011" is inserted into the BEI/BIAE field and the error count is ignored. Otherwise the error count (0-8) is inserted into the BEI/BIAE field. DAPI Operator specified 12 RES 15 16 31 32 11 PM APS/PCC 3 1 SM TCM1 IAE 2 10 TCM5 TCM2 1 0 TCM6 BDI GCC1 4 9 MFAS TCM ACT 2 8 63 Page39 OTUK SECTION MONITORING OVERHEAD 1 2 3 4 5 6 FAS 1 RES 3 TCM3 GCC2 TTI BIP-8 SAPI 15 16 APS/PCC 2 3 BEI/BIAE 4 5 6 7 RES DAPI 12 GCC0 TCM4 PM 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO defect indication (BDI) A single-bit BDI signal is defined to transmit the signal failure status detected by the section 8 termination sink function in the upstream direction. 31 32 11 RES Backward 3 1 0 TCM1 IAE 2 10 TCM5 BDI 1 9 SM TCM6 TCM2 GCC1 4 8 MFAS TCM ACT 2 7 BDI is set to "1" to indicate an OTUk backward defect indication; otherwise, it is set to "0". Operator specified 63 Page40 OTUK SECTION MONITORING OVERHEAD 1 2 3 4 5 6 7 FAS 1 2 RES 3 TCM3 9 MFAS TCM ACT TCM6 GCC2 10 SM TCM1 APS/PCC BIP-8 1 0 SAPI 15 16 2 3 BEI/BIAE 4 5 6 7 RES 63 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO alignment error (IAE) A single-bit IAE signal is defined to allow the S-CMEP been detected. DAPI IAE is set to "1" to indicate a frame alignment error; otherwise it is set to "0". RES Operator specified RES 15 that an alignment error in the incoming signal has 8 31 32 TCM4 14 ingress point to inform its peer S-CMEP egress point IAE TTI GCC0 13 RES 3 BDI 2 12 PM Incoming 1 11 TCM5 TCM2 GCC1 4 8 (reserved) Two bits are reserved (RES) for future international standardization. They are set to "00". Page41 OTUK GCC0 AND RES OVERHEAD 1 2 3 2 RES 3 TCM3 5 6 FAS 1 4 4 GCC1 7 8 9 MFAS TCM ACT TCM6 TCM2 GCC2 10 11 SM 13 GCC0 TCM5 TCM1 12 TCM4 PM APS/PCC RES 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO General communication channel (GCC0) Two bytes are allocated in the OTUk overhead to support a general communications channel between OTUk termination points. A clear channel is located in row 1 and columns 11 and 12. RES (reserved) Two bytes of the OTUk overhead are reserved for future international standardization. They are located in row 1 and columns 13 and 14. They are set to all “0”s. Page42 ODUK PATH MONITORING OVERHEAD 1 2 4 5 6 FAS 1 2 RES 3 TCM3 4 3 GCC1 7 TTI BIP-8 APS/PCC 3 BDI BEI TCM4 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO TTI / BIP-8 / BEI / BDI For path monitoring, this overhead’s functions are the same as those of the OTUk SM signal, except that BEI signals do not support the BIAE function. STAT 15 16 DAPI GCC0 13 RES 1 2 3 4 5 6 7 8 SAPI 12 PM 0 11 TCM5 TCM1 GCC2 10 SM TCM6 TCM2 2 9 MFAS TCM ACT 1 8 They are located in row 3 and columns 10 to 12. 31 32 Operator specified 63 Page43 ODUK PATH MONITORING OVERHEAD 1 2 3 5 6 FAS 1 3 TCM3 GCC1 TCM2 GCC2 1 2 TTI BIP-8 0 15 16 DAPI 31 32 Operator specified 9 BEI 10 SM 11 TCM1 TCM4 PM APS/PCC STAT 13 14 RES 8 15 16 17 RES JC FTFL RES JC EXP RES 5 6 7 12 GCC0 TCM5 3 1 2 3 4 SAPI 8 TCM6 BDI RES 7 MFAS TCM ACT 2 4 63 4 RES JC PSI NJO Status (STAT) For path monitoring, three bits are defined as status bits. They indicate the presence of a maintenance signal. Bit 678 Status 000 Reserved for future international standardization 001 Normal path signal 010 Reserved for future international standardization 011 Reserved for future international standardization 100 Reserved for future international standardization 101 Maintenance signal: ODUk - LCK Page44 ODUK TCM OVERHEAD 1 2 3 4 5 6 FAS 1 2 RES 3 TCM3 GCC1 4 7 8 MFAS TCM ACT GCC2 2 TTIi BIP-8i 10 SM TCM6 TCM1 RES 15 16 3 BEIi/BIAEi 4 5 BDIi SAPI 2 6 7 31 32 13 14 RES 15 16 RES JC FTFL RES JC EXP RES JC PSI NJO TTIi/BIP-8i/BEIi/BIAEi/BDIi For each tandem connection monitoring field, this overhead’s functions are the same as 8 those of OTUk SM signals. STATi DAPI TCM4 PM APS/PCC 3 1 12 GCC0 0 11 TCM5 TCM2 1 9 Six fields of the ODUk TCM overhead are defined in row 2 and columns 5 to 13, and row 3 and columns 1 to 9 of the ODUk overhead. Operator specific 63 Page45 ODUK TCM OVERHEAD 1 2 4 5 6 FAS 1 2 RES 3 TCM3 4 3 GCC1 7 GCC2 TTIi BIP-8i 5 6 7 8 BEIi/BIAEi 14 RES 15 16 17 RES JC FTFL RES JC RES JC PSI NJO STAT (status) 1 2 3 4 13 EXP RES STATi TCM4 PM APS/PCC 3 12 GCC0 TCM1 BDIi SAPI 11 TCM5 0 10 SM TCM6 TCM2 2 9 MFAS TCM ACT 1 8 For each tandem connection monitoring field, three bits are defined as status bits. They indicate the presence of a maintenance signal if there is an incoming alignment error at the source TC-CMEP, or if there is no source TC-CMEP active. 15 16 DAPI 31 32 Operator specified 63 Bit 678 000 001 010 Status No source TC In use without IAE In use without IAE 011 Reserved for future international standardization 100 Reserved for future international standardization 101 Maintenance signal: ODUk -LCK 110 Maintenance signal: ODUk -OCI Page46 NESTED AND CASCADED ODUK MONITORED CONNECTIONS TCM6 TCM6 TCM6 TCM6 TCM6 TCM6 TCM6 TCM5 TCM5 TCM5 TCM5 TCM5 TCM5 TCM5 TCM4 TCM4 TCM4 TCM4 TCM4 TCM4 TCM4 TCM3 TCM3 TCM3 TCM3 TCM3 TCM3 TCM3 TCM2 TCM2 TCM2 TCM2 TCM2 TCM2 TCM2 TCM1 TCM1 TCM1 TCM1 TCM1 TCM1 TCM1 A1 B1 C1 C2 B2 B3 B4 A2 C1 - C2 B1 - B2 B3 - B4 A1 - A2 TCMi TCM OH field not in use TCMi TCM OH field in use Page47 OVERLAPPED ODUK MONITORED CONNECTIONS TCM6 TCM6 TCM6 TCM6 TCM6 TCM5 TCM5 TCM5 TCM5 TCM5 TCM4 TCM4 TCM4 TCM4 TCM4 TCM3 TCM3 TCM3 TCM3 TCM3 TCM2 TCM2 TCM2 TCM2 TCM2 TCM1 TCM1 TCM1 TCM1 TCM1 A1 B1 C1 B2 C2 A2 C1 - C2 B1 - B2 A1 - A2 TCMi TCM OH field not in use TCMi TCM OH field in use Page48 ODUK TCM ACT COORDINATION PROTOCOL 1 2 2 RES 3 TCM3 4 5 6 FAS 1 4 3 GCC1 TCM ACT 7 9 MFAS TCM6 TCM2 GCC2 8 10 11 SM GCC0 TCM5 TCM1 12 TCM4 PM APS/PCC RES 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO TCM activation/deactivation (TCMACT) A one-byte TCM activation/deactivation field is located in row 2 and column 4. Its definition is to be defined in future. Page49 ODUK GCC1/GCC2 1 2 2 RES 3 TCM3 4 5 6 FAS 1 4 3 GCC1 TCM ACT 7 9 MFAS TCM6 TCM2 GCC2 8 SM 11 12 GCC0 TCM5 TCM1 APS/PCC 10 13 RES TCM4 PM 14 15 16 17 RES JC FTFL RES JC EXP RES RES JC PSI NJO General communication channel (GCC1/GCC2) Two fields of the two bytes are allocated in the ODUk overhead to support two general communication channels between any two NEs with access to the ODUk frame structure (for example, at 3R regeneration points). The bytes for GCC1 are located in row 4 and columns 1 and 2, and the bytes for GCC2 are located in row 4 and columns 3 and 4 of the ODUk overhead. Page50 ODUK APS/PCC CHANNEL 1 2 2 RES 3 TCM3 4 5 6 FAS 1 4 3 GCC1 TCM ACT 7 9 MFAS TCM6 TCM2 GCC2 8 SM 11 12 GCC0 TCM5 TCM1 APS/PCC 10 TCM4 PM RES 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO Automatic protection switching/protection communication control (APS/PCC) A four-byte ODUk-APS/PCC signal is defined in row 4 and columns 5 to 8 of the ODUk overhead. For linear protection schemes, bit assignments for these bytes and the bit oriented protocol are given in ITU-T G.873.1. Bit assignment and byte oriented protocol for ring protection schemes are to be defined in future. A maximum of eight levels of nested APS/PCC signals may be present in this field. Page51 ODUK FTFL CHANNEL 1 2 2 RES 3 TCM3 4 5 6 FAS 1 4 3 GCC1 TCM ACT 7 9 MFAS TCM6 TCM2 GCC2 8 SM 10 11 GCC0 TCM5 TCM1 12 TCM4 PM APS/PCC RES 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO Fault Type & Fault Location (FTFL) One byte is allocated in the ODUk overhead to transport a 256-byte FTFL message. The byte is located in row 2 and column 14 of the ODUk overhead. The 256-byte FTFL message consists of two 128-byte fields. The forward field is allocated in bytes 0 to 127 of the FTFL message. The backward field is allocated in bytes 128 to 255 of the FTFL message. Page52 ODUK EXPERIMENTAL AND RESERVED OVERHEAD 1 2 4 5 6 FAS 1 2 RES 3 TCM3 4 3 GCC1 TCM ACT 7 8 9 MFAS TCM6 TCM2 GCC2 SM 11 12 GCC0 TCM5 TCM1 APS/PCC 10 TCM4 PM RES 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO Experimental (EXP) Two bytes are allocated in the ODUk overhead for experimental use. They are located in row 3 and columns 13 and 14 of the ODUk overhead. There is no requirement for forwarding the EXP overhead over different (sub)networks. RES 9 bytes are reserved in the ODUk overhead for future international standardization. They are located in row 2 and columns 1 to 3, and row 4 and columns 9 to 14 of the ODUk overhead. They are set to all “0”s. Page53 OPUK PAYLOAD STRUCTURE IDENTIFIER 1 2 3 4 5 6 FAS 1 2 RES 3 TCM3 GCC1 4 0 8 9 MFAS TCM ACT TCM6 TCM2 GCC2 PT 10 11 SM 12 GCC0 TCM5 TCM4 TCM1 PM APS/PCC RES 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO Payload structure identifier (PSI) 1 One byte is allocated in the OPUk overhead to transport a 256-byte payload structure Mapping and concatenation specific 255 7 identifier (PSI) signal. It is aligned with the ODUk multiframe. PSI[0] contains a one-byte payload type. PSI[1] to PSI[255] are mapping and concatenation specific. Page54 PAYLOAD TYPE CODE POINTS MSB 1234 LSB 1234 Hex Code 0000 0001 01 Experimental mapping 0000 0010 02 Asynchronous CBR mapping 0000 0011 03 Bit synchronous CBR mapping 0000 0100 04 ATM mapping 0000 0101 05 GFP mapping 0000 0110 06 Virtual Concatenated signal 0001 0000 10 Bit stream with octet timing mapping 0001 0001 11 Bit stream without octet timing mapping 0010 0000 20 ODU multiplex structure 0101 0101 55 Not available 0110 0110 66 Not available 1000 xxxx 80-8F 1111 1101 FD NULL test signal mapping 1111 1110 FE PRBS test signal mapping 1111 Page55 1111 FF Not available Meaning Reserved codes for proprietary use OPUK MAPPING SPECIFIC OVERHEAD 1 2 4 5 6 FAS 1 2 RES 3 TCM3 4 3 GCC1 TCM ACT 7 9 MFAS TCM6 TCM2 GCC2 8 SM 11 12 GCC0 TCM5 TCM1 APS/PCC 10 TCM4 PM RES 13 14 RES 15 16 17 RES JC FTFL RES JC EXP RES JC PSI NJO Justification control/negative justification opportunity/reserved (JC/NJO/RES) Seven bytes are reserved in the OPUk overhead for the mapping and concatenation specific overhead. These bytes are located in rows 1 to 3 and columns 15 and 16, and row 4 and column 16. 255 bytes in the PSI are reserved for mapping and concatenation specific purposes. Page56 THANKS FOR BEING PATIENT 57
