1. C L Morgan CS 4594 Broadband Communications Digital Wrapper

2. C L Morgan Digital Wrapper (DW) Standardized by ITU-T as G.709 Standardized by ITU-T as G.709 DW is Time Division Multiplexing (TDM). DW is Time Division Multiplexing (TDM). Types of traffic: IP, Ethernet (GFP), ATM, SONET/SDH Types of traffic: IP, Ethernet (GFP), ATM, SONET/SDH Bit rates: 2.488 Gbps, 9.95 Gbps, 39.81 Gbps Bit rates: 2.488 Gbps, 9.95 Gbps, 39.81 Gbps Connection monitoring – even over several carriers Connection monitoring – even over several carriers Forward error correction (FEC) correct and detect Forward error correction (FEC) correct and detect

3. C L Morgan DW layers Och OMS OTS

4. C L Morgan DW layer encapsulation OTU OH ODU FEC ODU OH OPU OPU OH Client Payload Client Payload OPU = Och payload unit ODU = Och data unit OTU = Optical Transport Unit

5. C L Morgan DW Frame structure FASOT UOH ODU OH OPU OH FEC Client payload 12341234 1 7 8 14 15 16 17 3824 3825 4080

6. C L Morgan OPU Overhead Rows 1 to 4, columns 15,16 Rows 1 to 4, columns 15,16 Created at the point where client signal is generated Created at the point where client signal is generated Used at point where client signal is terminated Used at point where client signal is terminated PSI = Payload Structure Identifier (row 4 column 15, used to transmit 256 byte message over multiframe, first byte is payload type PSI = Payload Structure Identifier (row 4 column 15, used to transmit 256 byte message over multiframe, first byte is payload type Rest are reserved Rest are reserved

7. C L Morgan ODU Overhead Rows 2 to 4, columns 1,14 Rows 2 to 4, columns 1,14 PM = Path monitoring overhead PM = Path monitoring overhead Monitoring over sections and fault locationMonitoring over sections and fault location TCM = tandem connection monitoring overhead TCM = tandem connection monitoring overhead Signal management over multiple networksSignal management over multiple networks

8. C L Morgan ODU Overhead FASOT UOH ODU OH OPU OH FEC Client payload 12341234 1 7 8 14 15 16 17 3824 3825 4080 RES TCM3 GCC1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 TMC/ ACT TMC2 GCC2 TMC6TMC5TMC4FTFL TMC1PMEXP APS/PCCRES

9. C L Morgan ODU Overhead RES: reserved RES: reserved TCM/ACT: Activation/deactivation of TCM TCM/ACT: Activation/deactivation of TCM TCM: Tandem connection monitoring TCM: Tandem connection monitoring FTL: Fault type and fault location reporting channel FTL: Fault type and fault location reporting channel PM: Path monitoring PM: Path monitoring EXP: reserved for experimental EXP: reserved for experimental GCC: General communication channel GCC: General communication channel APS/PCC: Automatic protection switching and protection communications channel APS/PCC: Automatic protection switching and protection communications channel

10. C L Morgan FAS and OTU overhead FASOTU OH ODU OH OPU OH FEC Client payload 12341234 1 7 8 14 15 16 17 3824 3825 4080 FAS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 MFAS SMGCCRES

11. C L Morgan FAS and OTU overhead _ FAS = frame alignment signal (row 1, columns 1- 7) (unscrambled) F6F6F6282828h F6F6F6282828h _ MFAS – multi-frame alignment signal (column 7) – counts frame number in a 256 multiframe _ (scrambled with rest of frame) _ SM – section monitoring – info for 3Rs : retiming, reshaping, regeneration _ GCC general communication channel

12. C L Morgan FEC _ Rows 1 to 4, Columns 3825 to 4080 _ Uses Reed-Solomon code RS (255/239)