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Optical Networks Evolution

Optical Networks Evolution. Single Wavelength Transmission. Multi-Wavelength Transmission. Multi-Wavelength Networking. Evolution of Optical Networks. Improved Costs. Greater Network Scale. Requisites Traffic Continues to Grow Reducing Networking Costs Is A Priority.

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Optical Networks Evolution

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  1. Optical NetworksEvolution

  2. Single Wavelength Transmission Multi-Wavelength Transmission Multi-Wavelength Networking Evolution of Optical Networks Improved Costs Greater Network Scale Requisites • Traffic Continues to Grow • Reducing Networking Costs Is A Priority

  3. Single Wavelength Transmission 1 Wavelength Per Fiber 1 Wavelength per Network Element • Long haul traffic aggregation • Narrowband traffic • Reliable transmission • Efficient tributary access • Service level switching • Isolated knowledge • “Dumb pipes” SDH-MUX SDH-MUX Electronic Regeneration Electronic Multiplexing

  4. TDM MUX FOTS 1545 1555 1550 Wavelength (nm) TDM Transmission Composite Optical Signal Signals are multiplexed in the time domain Rx TDM MUX Byte Interleave Tx Rx Rx OC-48/192 Rx OC-3/12 • Single wavelength per fiber • Multiple channels per fiber • Sync and async signals are muxed to a single higher optical bit rate • E/O signal conversion

  5. SONET Optical Carrier (OC) and SDH Synchronous Transport Module (STM) Levels Optical Level Line Rate (Mbps) Payload Rate (Mbps) Overhead Rate (Mbps) Electrical Level 1.728 OC-1 STS-1 51.840 50.112 5.184 OC-3/STM-1 STS-3 155.520 150.336 15.552 OC-9/STM-3 STS-9 466.560 451.008 OC-12/STM-4 STS-12 622.080 601.344 20.736 OC-18/STM-6 STS-18 933.120 920.016 31.104 OC-24/STM-8 STS-24 1244.160 1202.688 41.472 OC-36/STM-13 STS-36 1866.240 1804.032 62.208 OC-48/STM-16 STS-48 2488.320 2405.376 82.944 OC-96/STM-32 STS-96 4976.640 4810.752 165.888 OC-192/STM-64 STS-192 9953.280 9621.504 331.776 SONET Overhead is 3% independent of Data Rate

  6. SDH Components andOverhead Layers Path Multiplex Section Multiplex Section Regenerator Section Regenerator Section REG REG PTE (ADM, DSLAM,… PTE (ADM, DSLAM,… ADM or DCS Path Termination Path Termination Regenerator Section Termination Regenerator Section Termination Multiplex Section Termination PTE = Path Terminating Element MUX = Terminal Multiplexer REG = Regenerator ADM = Add/Drop Multiplexer DCS = Digital Cross-Connect System Service (E1, E3…) Mapping Demapping Service (E1, E3…) Mapping Demapping

  7. The Basic Building Block of SDH: STM-1 • Basic building block: SDH STM-1 frame • 9 columns of SDH transmission overhead (x9, byte rows) = 81 bytes • 261 cols of STM-1 “administrative units group (AUG)” (x9, byte rows) = 2349 bytes • 125 microseconds/frame = 155,52 (150,34) mbps Section Trace STM-1 AUG (261 Byte/Columns) APS Signaling J1 A1 A1 A1 A2 A2 A2 J0 x x Order ofTransmission Regenerator Section Overhead (3 Byte/Rows,9 Columns) B3 B1 x x E1 x x F1 x x 1 C2 D1 x x D2 x x D3 D2 x G1 AU Pointers 2 F2 B2 B2 B2 K1 x x K2 x x Multiplex Section Overhead (5 Byte/Rows,9 Columns) H4 D4 x x D5 x x D6 x x F3 D7 x x D8 x x D9 x x K3 D10 x x D11 x x D12 x x Bit Errors N1 S1 x x x x M1 E2 x x Path Overhead 1 Row x 9 Columns Total STM-1 Transmission Overhead 9 Rows x 9 Columns Path Signal Label

  8. POS Standards Based Encapsulation • Telcordia GR-253 • ITU-T G.957 • ITU-T G.958 Section + Line OH Path OH Concatenated Payload FCS 16/32 Flag 8 Address 8 Control 8 PPP Packet Flag 8 Point-to-Point Protocol, IETF RFC 1661 PPP in HDLC Like Framing, IETF RFC 1662 Packet over SONET/SDH, IETF RFC 2615

  9. Working Router TX RX Optical Cloud Cisco’s Protect Group Protocol via IP ADM Protect Router SONET APS signaling protocol (K1/K2 BYTES) POS Provides Fast Restoration • Protection Switching - DWDM • Optical protection protects transmission infrastructure • Layer 3 provides path restoration • Opportunity for differentiation at the service level (Load-Balancing & MPLS-TE) Protection switching - ADM • Support both SONET APS and SDH MSP protocols • Protection for port, LC or chassis

  10. Connect to tributary interfaces on SONET/SDH muxes (OC3c/STM1c to OC48c/STM16c) Backbone Routers • Connect to transponders in a WDM system (typically OC12c/STM4c or OC48c/STM16c) Edge Routers POS Applications • Interconnect GSR directly over dark fiber • with regenerators to extend the distance of LR interfaces (typically OC48c/STM16c) • within a POP (typ. OC3c/STM-1 or OC-12c/STM-4c)

  11. Dynamic Packet Transport (DPT) • Eliminate SONET/SDH equipment while retaining benefits • Destination stripping • Bandwidth consumed only on traversed segment • No dedicated restoration bandwidth • Dynamic, per-packetspatial reuse • Control via SRP-fa instead of token passing DPT Ring Working BFP

  12. TTL RI DS PRI Mode Usage P Destination Address Source Address Protocol Type : : : : Payload FCS Spatial Reuse Protocol SONET/SDH Frame Path Over- head Section plus Line Overhead Concatenated Payload • New layer 2 MAC technology SRP • Spatial Reuse Protocol • Uses SONET/SDH framing • Bandwidth efficient • Fairness (SRP-fa) • Scalable • Fast protection switching and service restoration • Multicasting and priority (CoS)enables DPT functionality MAC Frame … MAC IP Packet MAC IP Packet DPT Packet Format

  13. DPT Fairness Example (1) (2) • DPT fairness algorithm • Distributed algorithm • Propagates and uses MAC usage info • Rate controlsfor sourced andforwarded traffic • Rapid adaptation and convergence • Transitive control (4) (3) A (4) B

  14. 622Mbps E D C B 200Mbps 200Mbps 200Mbps 200Mbps 155Mbps 155Mbps 155Mbps 155Mbps DPT-fa Operation Example A Sink

  15. (1) (2) (4) (3) (4) A B Fiber Cut DPT Features DPT Packet Processing Tx Queuing Rx Queuing Layer 3 Switching SRP Fairness Algorithm Transit Buffer Tx Queue Rx Packets Intelligent Protection Switching Tx Fiber Rx Fiber SRP MAC Layer Tx Fiber Rx Fiber Detects Alarms and Events and Wraps Ring ~100 ms

  16. DPT Cooperates With Layer 3 CoS to Extend Functionality Precedence Setting Rate Control Layer 3—IP Congestion Control RED/WRED Granular Scheduling DRR on Eight Classes Big Fat Pipes Low-Priority Fairness Layer 2— SRP MAC High-Priority Bypass Precedence Mapping • Layer 3 provides rich functionality and granular controls • MAC provides speed and simplicity • Enables low delay/jitter for voice and video packets

  17. Network Architecture Migration Backbone ~ ~ WDM ~ ~ ~ ~ Si Si Si Si Si Si GSR GSR GSR Packet Concentrator LeasedLines 10Gb Regional Transport Ring Dedicated Access PoP Ring Building Access Mux GSR Cable Data Ring 2.4G Metro Access Ring

  18. Multi-Wavelength Transmission Single Wavelength Transmission Multi-Wavelength Networking Evolution of Optical Networks Improved Costs Greater Network Scale

  19. Reamplify Reshape Retime Rx Tx Laser Rx DWDM System Design 1550 0 0 1551 1 1 1552 2 2 1553 3 Optical Combiner 3 DWDM Filter 1554 4 4 1555 5 5 Amplify 1556 6 6 1557 7 7 1310 nm 15xx nm 15xx nm 1310 nm External Modulator

  20. Receive 3R Transmit 0 1550 1 1 0 1551 2 2 1552 3 3 4 1553 4 20 ppm 5 1554 5 50 ppm 6 6 1555 PLL 7 7 1556 1557 0 0 Transmit Receive 3R 1 50 ppm 1 2 2 1550 LOOP TIMING PLL 3 3 1551 4 4 1552 5 5 1553 6 6 1554 7 7 1555 1556 1557 Optical IP - using WDM

  21. Multi-Wavelngth Transmission “N” Wavelengths Per Fiber 1 Wavelength per Network Element • Fiber exhaust due to traffic growth • Increased data use • Higher data rates • Enabling technologies • DWDM - fiber savings • EDFAs – regenerator savings • Transparent fiber aggregation “Virtual Fiber” . . . . . .

  22. Tx Tx Tx Tx Rx Rx Rx Rx DWDM Transmission Signals are multiplexed in the wavelength domain Composite Optical Signal • Multiple wavelengths per fiber • Multiple channels per wavelength (TDM) • Statistically multiplexed data traffic • No signal format conversion WDM MUX · · · · · · 1530 1550 1565 Wavelength (nm) OC-48 x 40 ch. = 100 G/bs OC-192 x 16 ch. = 160 G/bs OC-48 x 80 ch. = 200 G/bs OC-48/192

  23. ITU Wavelength Grid l 1553.86 nm 1530.33 nm • ITU-T l grid is based on 191.7 THz + 100 GHz • Its purpose is to standardize lasers not DWDM systems • There is no standard for DWDM systems • Number and spacing of ls are design variables 0.80 nm

  24. EDFA Schematic ... EDF EDF WDM Coupler WDM Coupler ... Optical Filter Optical Isolator Optical Isolator DCF 1480 Pump Laser 980 Pump Laser • EDFAs amplify all ls in 1550 window simultaneously • Key performance parameters include • Saturation output power, noise figure, gain flatness/passband

  25. Anatomy of a DWDM System Terminal B Terminal A D E M U X Transponder Interfaces M U X Transponder Interfaces Post- Amp Pre- Amp Line Amplifiers Direct Connections Direct Connections Basic building blocks • Optical amplifiers • Optical multiplexers • Stable optical sources

  26. Basic Optical Protection Working • Protection migrates toDWDM equipment • Only 1 DWDM with protection modules needed • Switching decision controlled by transponders • Technologies include optical switching and OA gating Protect

  27. DWDM State-of-the-art • Point-to-point systems • 40l x OC-48 deployed • 16l x OC-192 deployed • 160l x OC-192 announced • Configurable OADMs • Metro rings Data Rate 1-10 Tbps per fiber is just around the corner!

  28. Multi-Wavelength Networking Single Wavelength Transmission Multi-Wavelength Transmission Evolution of Optical Networks Improved Costs Greater Network Scale

  29. “Virtual Transport” . . . . . . Multi Wavelength Networking “N” Wavelength Per Fiber “N” Wavelength per Network Element • Network and operations scaling v.S. Raw capacity • Single wavelength elements not keeping pace • Operations need to scale • Enabling technologies • Scalable and ultra dense architectures of electronic • Networking intelligence

  30. Intelligent Optical Transport Network Traditional Static Transport Network Moving From Static to Intelligent Intelligent Optical Networks Virtual Transport Networks Dynamic Provisioning Flexible Capacity Flexible Protection Point-to-Point WDM Physical Transport Overlays Static Provisioning Limited Line Rate Linear or Ring Protection Reduces total Cost of Ownership

  31. Distributed Intelligence Layer 3 IP Layer 2 ATM Layer 1 Voice/P.L. Emergence Of Intelligent Optical Core Scalable and Granular Capacity STM-1 to Wavelengths Full Suite of Protection Methods Provisioning & Intelligent Grooming

  32. Next Generation Optical Protection • Protection controlled by large cross-connects on tributary side of DWDM running a routing protocol • Protection migrates from fiber to l level • Line, ring and mesh restoration options

  33. Flexible & Rapid Restoration • Restore virtual wavelength paths end-end in 50ms using a wavelength routing protocol • Linear, ring & mesh options • No preplans, no dedicated restoration bandwidth • Wavelength routing protocol will be very similar to IP+ATM MPLS approach Multiprotocol Lambda Switching

  34. Fabric Fabric Fabric Fabric All Optical Networking Multi-Wavelength Networked Transparent Services • Optical dial tone • O-E sub-systems present only at network end points • Potential for cost savings • No more equipment upgrades? • Enabling technologies: • Lower cost optical systems • Ubiquitous compliance to optical standards • Optical OAM&P • No need for granular capacity

  35. Optical CrossConnect with Full Wavelength Conversion Wavelength Converters l 2 l 1 l l l l l l 1, 2, ... , n 1, 2, ... , n l l 2 1 1 1 l l n n • M demultiplexers at incoming side • M multiplexers at outgoing side • Mn x mn optical switch has wavelength converters at switch outputs l l 1 1 l l l l l l 1, 2, ... , n 1, 2, ... , n l l 2 2 2 2 l l n n . . . . . . l l 1 n l l l l l l 1, 2, ... , n 1, 2, ... , n l l 2 1 m m l l n 2 Wavelength Wavelength Optical CrossBar Demux Mux Switch

  36. Optical Add/Drop Multiplexer Trunk port Trunk port l 2 l 1 l l l 1, 2, ... , n l l l 1, 2, ... , n l l 1 2 • OADM similar to OXC • uses only 2 trunk ports • uses remaining incoming ports as Add-ports • uses remaining outcoming ports as Drop-ports1 in out l l n n

  37. Wavelength Routing • Streamline layers, remove functional overlap • Deliver optical transport and traffic-engineering at wavelength level complementing IP, MPLS • New functions • Rapid end-to-end provisioning • Fast path restoration • Bandwidth efficiencies

  38. Questions ???

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