Architectural Evolution of Transport Provider Networks Randy Zhang BRKSPG-2525

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1 Architectural Evolution of Transport Provider Networks Randy Zhang BRKSPG-2525

2 Agenda Transport providers challenges and solutions Agile lambda layer 100G and beyond Sub-lambda grooming Multilayer convergence and orchestration

3 Traffic Growth Continues Annual global IP Traffic (EB) Monthly Per User Traffic (GB) Compounded Annual Growth Rate: 19% Compounded Annual Growth Rate: 23% Source: Cisco VNI

Traffic Outpaces Revenue Global Service Provider Data 2005 2012 Compound Annual Growth Rate

4 Traffic Outpaces Revenue Global Service Provider Data Compound Annual Growth Rate (CAGR) Revenue Growth 5% Capex Growth 5% Bandwidth Growth 30% 70% Infonetics Research, Inc 2014

changes: Controlling Capex while growing capacity Opex reduction Improving utilization Reduce cost

5 The Provider Dollar Gap What should operators do: Generate new sources of revenue or increase service velocity Exponential Traffic Growth Declining Revenue per bit Reduce cost via incremental changes: Controlling Capex while growing capacity Opex reduction Improving utilization Reduce cost via architectural changes: Converging layers and products Application driven programmability Virtualization

6 Business Challenges Network Simplification: Expense Reduction ~20% Service innovation: ~17% new revenue Reputation Cost Profitability Agility: Service creation from quarters to days Risk Success Experience Growth

7 What solutions are available to meet these business challenges?

8 Grow Network Capacity and Agility Integrate wavelength layer with high-degrees of wavelength division multiplexing Increase number of wavelengths and spectral bandwidth per fiber Increase per wavelength bit rate Create a mesh network with any to any connectivity

Increase Wavelength Utilization Wavelength is one of the most

Aggregation OTN OTN / Packet Optimized DWDM wavelength today

10G and below Sub-wavelength layer switching or grooming via

greater wavelength utilization λ1 Private Line Private Line

Line Private Line Private Line Private Line λ2 Private Line

9 Increase Wavelength Utilization Wavelength is one of the most important resources for a transport provider OTN Only Packet Aggregation OTN OTN / Packet Optimized DWDM wavelength today is typically 40G or 100G, client service varies, typically 10G and below Sub-wavelength layer switching or grooming via Optical Transport Network (OTN) and packet transport for greater wavelength utilization λ1 Private Line Private Line Private Line Private Line λ2 Source: Infonetics λ1 Private Line Private Line Private Line Private Line λ2 Private Line Private Line Private Line Private Line λ1 Not yet needed Money saved λ2 deferred

Integrate and Delayer Integrate layers IP/MPLS/OTN/DWDM to eliminate internal interfaces and intermediate OEO layers Simplify architecture by

coordinated protection and maintenance Protection: predesignated facility for fast switchover Restoration: dynamic switchover for second level

10 Integrate and Delayer Integrate layers IP/MPLS/OTN/DWDM to eliminate internal interfaces and intermediate OEO layers Simplify architecture by collapsing and removing layers IP and Optical Integration Hardware level Management and control plane Enhance resiliency and availability with coordinated protection and maintenance Protection: predesignated facility for fast switchover Restoration: dynamic switchover for second level service restoration IP/MPLS' Service' GMPLS' WSON' Network Op miza on Server Network Collec on / Deployment Plug-Ins Service' Packet' OTN' Packet'NE' OTN'NE' DWDM'NE' DWDM'

Automate Automate manual processes and reduce service turn-up time Virtualization: OS, topology and service Use dynamic control plane for service provisioning Application programmable Multilayer and

11 Automate Automate manual processes and reduce service turn-up time Virtualization: OS, topology and service Use dynamic control plane for service provisioning Application programmable Multilayer and multidomain orchestration Inventory Base Services Functions DB North Bound APIs Service Management Functions Base Network Management Functions Topology Config Fault Assurance SW Mgmt Device Access Functions Protocol Abstraction Layer SNMP OpenFlow HTTP/XML Netconf

12 A Winning Strategy Preserve What Is Working Resiliency Scale Rich feature set Evolve for Emerging Requirements + Automation = Convergence Virtualization Application interaction Achieve Business Objectives Service agility and velocity Simplified operations Higher value services Evolved Programmable Networks

13 Network Layers of Transport Providers IP/MPLS (L3/L2.5) IP IP IP IP Ethernet (L2) TDM Voice TDM Private Line ESCON FC Alien Wavelengths SONET/SDH (L1) Optical Transport Network (L1) Wavelength (L0)

14 Key Attributes of Next Generation Transport Architectures A wavelength layer that is agile and of high capacity: Reconfigurable any to any connectivity without blocking 100G and beyond per channel with flexible wavelength structure Sub-lambda layer switching to increase wavelength utilization Multilayer convergence: IP and optical convergence Multilayer orchestration: automation, programmability, and virtualization

15 Agile Lambda Layer

16 Fiber Optics and Wavelength Division Wavelength Division Multiplexing (WDM) Dense WDM (DWDM): >= 32 channels Coarse WDM (CWDM): <= 16 channels Terminology: wavelength, frequency, lambda, channel, color Fiber traffic capacity Ch count i=1 bit rate at Ch i Fiber 50 GHz.4 nm Frequency (THz) Wavelength (nm) ITU Wavelength Grid

17 Communication Wavelengths Loss (db)/km S Band C Band L Band 2.0 Intermediate reach Long reach 0.5 Short reach Wavelength (nm) UltraViolet Visible InfraRed

18 Point to Point DWDM Network * Showing one direction Client Transponder ITU Wavelengths Transponder Client Tx Rx OEO OEO Rx Tx Tx Rx OEO OA OA OEO Rx Tx OEO: Optical-Electrical-Optical conversion OA: Optical Amplifier

19 Optical Add/Drop Multiplexer (OADM) Channels are added to or dropped from the network Some channels are passed through (expressed) * Showing one direction Drop Channel Site 2 Add Channel Site 1

20 Fixed OADM (FOADM) Network topology and channel capacity at each node are fixed at network design time Changing topology and capacity requires physical change (truck roll) and retuning, and results in service outage Need multiple spares, as the FOADM units are wavelength specific Traffic forecast may not be accurate Network hard to maintain

21 Reconfigurable OADM (ROADM) Network planning done one time during network design with all channels available at each node Changing topology and capacity by software Good fit for packet traffic Control plane protocols further reduce change overhead Minimal Opex and Capex for growth and improved network performance

22 ROADM in a Nutshell * Showing one direction Local Drop Local Add Line In drop block drop block Add Pass Line Out Splitter Express Pass Add Wavelength Selective Switch (WSS) Per channel selection controlled by software

23 First Generation ROADM Pass-through channels are reconfigurable at all intermediate points. Manual change at Add/Drop points Colored: fixed wavelength assigned to an Add/Drop port with a patch cable, changing wavelength requires moving cables between transponder and mux/demux Directional: a mux/demux combo is assigned to a fixed line direction 2 degree nodes only 100 GHz spacing

24 Colored and Directional ROADM Fixed wavelength on Mux and Demux ports West Split WSS East Fixed direction for Add and Drop WSS Split Demux Mux Mux Demux East West

25 The Cases for Colorless and Directionless ROADM Mesh network Bandwidth on-demand Dynamic restoration

26 Colorless and Directionless ROADM Degree A Split WSS Degree B Patch Panel Split WSS Degree C Color selective at Add/Drop with WSS All degrees available at Add/Drop WSS Split WSS WSS A B Add Drop C

Contentionless ROADM, Flexible Grid and Modulations Contentionless ROADM

400 Gbps 1 Tbps 1 Tbps 100 Gbps M Add/Drop Ports 1 - Odd 1- Even 2 - Odd 2 -

Any color from a degree can be dropped or added to any port Not limited by ITU

27 Contentionless ROADM, Flexible Grid and Modulations Contentionless ROADM Flexible Grid ROADM Flexible Modulations N degrees NxM Switch 100 Gbps 100 Gbps 400 Gbps 1 Tbps 1 Tbps 100 Gbps M Add/Drop Ports 1 - Odd 1- Even 2 - Odd 2 - Even 3 - Odd 3 - Even 4 - Odd 4 - Even 5 - Odd 5 - Even 6 - Odd 6 - Even 7 - Odd Any color from a degree can be dropped or added to any port Not limited by ITU Grid (gridless) to form super channels Choice of modulations based on bit rate and distance

28 DWDM Control and Management Planes Wavelength Switched Optical Network (WSON): LSP = wavelength; optical impairments awareness Dynamic light path setup, re-routing and restoration; programmable Automatic Power Control (APC): Automatically regulates amplifier and attenuator for capacity change, aging effects, operating conditions Cisco Transport Planner (CTP): DWDM design and planning tool Automatic Network Setup (ANS): CTP assisted network turn-up

Directionless, Contentionless (CDC) Flexible grid Dynamic control

29 Summary Today s traffic requires fully flexible wavelength layer New generations of ROADMs provide the agility with: Colorless, Directionless, Contentionless (CDC) Flexible grid Dynamic control plane and management plane lead to simplified operations: WSON, APC, CTP, ANS NCS 2000

30 100G and Beyond

31 Drivers for 100G DWDM Relieving fiber exhaustion due to wide deployment of 10G clients Continued increase of client rates Power and space saving: potentially more than 50% reduction in carbon footprint in a 10-year lifecycle (than 10G) Operational efficiency: Lower cost of managing and maintaining reduced number of boxes and links Better trunk utilization without resorting to load sharing with lower speed links Reducing overall network latency: Coherent receivers eliminate the extra fiber due to dispersion compensation

32 Requirements for 100G DWDM Compared to 10G Higher Optical Signal to Noise Ratio (OSNR) Lower Chromatic Dispersion (CD) tolerance Lower Polarization Mode Dispersion (PMD) tolerance OSNR Spreading of pulse due to CD Spreading of pulse due to PMD Signal level Bit 1 Bit 2 Bit 1 Bit 2 Noise level

33 100G Technology Summary Transmitter Decrease baud (symbol rate) to lower impairments Use a complex modulation scheme: more bits are carried per baud Split signal into two polarizations: higher optical efficiency Receiver Coherent receiver using Digital Signal Processor (DSP) Forward Error Correction (FEC) Use third generation FEC to extra coding gain

34 Modulation Examples (N)RZ (Non) Return to Zero DPSK Differential Phase Shift Keying Amplitude Phase Polarization DPSK DQPSK PM- X RZ NRZ QPSK Amplitude DQPSK Differential Quadrature Phase Shift Keying QPSK Quadrature Phase Shift Keying PM- X Polarization Multiplexing, X can be DPSK, DQPSK, QPSK, etc Phase Shift

35 100G Modulation (PM-QPSK) (a) Quadrature Phase Shift Keying (QPSK) (b) Polarization Multiplexing (PM) QPSK: Encode each symbol using 4 different phases (2 bits) PM: Signal multiplexed from two polarizations Final symbol rate at about 25 Gbaud

36 Coherent Detection DCU: Dispersion compensation unit Add local light source to the incoming signal When the frequency matches, the signal is stronger; else signal filtered Digital signal processor for impairment correction DCU DCU DCU DD Direct Detection CD Coherent Detection

37 Forward Error Correction (FEC) ITU introduced FEC as part of Optical Transport Network (OTN) standard First and second generations FEC generate 6-9 db coding gain Third generation FEC can increase coding gain of 9-12 db FEC adds about 7-20% overhead Information k Redundant r

38 Summary 100G DWDM brings more capacity and efficiency Technology challenges: lower effective bit rate, higher OSNR Higher OSNR means higher reach and lower cost 100G DWDM technology: Enhanced transmitter technologies: lower effective bit rate using complex modulation schemes Coherent detection Third generation FEC

Beyond 100G Rates beyond 100G require even more complex modulation schemes Higher order Quadrature Amplitude Modulation (QAM) generates more code points to

39 Beyond 100G Rates beyond 100G require even more complex modulation schemes Higher order Quadrature Amplitude Modulation (QAM) generates more code points to further reduce baud 16-QAM modulates both amplitude and phase to generate 16 code points (4 bits per symbol) Next levels up: 200G, 250G 16-QAM Constellation

40 Max Distance (km) Capacity, Distance and Modulation PM-BPSK PM-QPSK BPSK: Binary Phase Shift Keying PM: Polarization Multiplex QAM: Quadrature Amplitude Modulation QPSK: Quadrature Phase Shift Keying PM-8QAM PM-16QAM Capacity (Tb/s)

41 Sub-lambda Grooming

42 Sub-lambda Grooming via OTN Optical Transport Network (OTN) ODU0 ODU2 ODU0 ODU0 ODU0 ODU0 ODU1 OTU4 Lambda Fiber

43 Optical Transport Network (OTN) Defined by ITU G.709 with an original purpose of providing a digital wrapper for SONET/SDH payloads over DWDM wavelength Forward Error Correction (FEC) to improve the reach Extensive overhead bytes for error and performance monitoring (operations, administration, maintenance, and provisioning, OAM&P) at wavelength levels Native support for Ethernet rates and grooming hierarchy

44 Network Layers IP/MPLS (L3/L2.5) IP IP IP IP Ethernet (L2) TDM Voice TDM PL ATM ESCON FC Alien Wavelengths SONET/SDH (L1) OTN (L1) WDM (L0)

45 OTN Layers and Mapping Electrical Domain Client Payload OH Client Payload Optical Payload Unit (OPU) OH OH Client Payload Optical Data Unit (ODU) OH OH OH Client Payload FEC Optical Transport Unit (OTU) Optical Domain Optical Channel

OTN Framing 1 1 7 8 14 17 3824 3825 4080 FAS OTU OH 2 3 ODU OH Client Payload FEC 4 Fixed frame size Frame rate designated by number k, standard k=0, 1, 2, 2e, 3, 4 for ODU

46 OTN Framing FAS OTU OH 2 3 ODU OH Client Payload FEC 4 Fixed frame size Frame rate designated by number k, standard k=0, 1, 2, 2e, 3, 4 for ODU Minimum OTU rate is OTU1 ODUflex OPU: Optical Payload Unit ODU: Optical Data Unit OTU: Optical Transport Unit FAS: Frame Alignment Signal FEC: Forward Error Correction OH: Overhead

47 OTN Rates Hierarchy Frame Period (µsec) OTU Bit Rate (kbps) Payload Capacity (kbps) Examples of Multiplexing or Payload ODU0/OPU N/A 1,238, xGigE OTU ,666, ,488, xODU0s OTU ,709, ,995, xODU1s, 8xODU0s OTU2e ,095,727 10,356, x10GBASE-R OTU ,018, ,150, xODU2s, 16xODU1s OTU ,809, ,355, x100GBASE-R, 2xODU3s

48 ODU Grooming and Channelization Client payload may be mapped into a Low-Order (LO) ODUj, which can be Transported directly over OTUk (where j = k), or Multiplexed into a High-Order (HO) ODUk (where j < k) LO ODU, sub-wavelength level; HO ODU, wavelength level G.709 defines strict and complex multiplexing hierarchy ODU grooming allows packing lower-rate client traffic streams into a single, high-rate wavelength

49 Circuit Transport vs Packet Transport Minimum ODU container is 1.25G (ODU0) Inefficient bandwidth use for OC3, OC12, DS3, DS1 Circuit emulation with packet transport MPLS-based packet transport for high scalability OTN and packet optimized solutions Circuit Packet

50 Summary OTN can function as a digital wrapper over an optical channel Power of OTN is its ODU grooming hierarchy ODU aggregation allows better channel utilization Optimized circuit and packet transport

51 Multilayer Convergence and Orchestration

52 Network Layers of Transport Providers IP/MPLS (L3/L2.5) IP IP IP IP Ethernet (L2) TDM Voice TDM Private Line ESCON FC Alien Wavelengths SONET/SDH (L1) Optical Transport Network (L1) Wavelength (L0)

53 Traditional Hierarchical Model General purpose line cards supporting core and edge applications with full IP/MPLS feature set IP/MPLS (L3/L2.5) Core WDM (L0)

54 Benefits and Challenges of Hierarchical Model Benefits Better bandwidth use via statistical multiplexing Fewer, and typically larger, links to administer in the core Simpler capacity planning: edge based on edge aggregate traffic demands and core based on highly aggregated more predictable traffic demands Challenges Much more expensive than TDM infrastructure Potentially multiple levels of core routers to build the routing hierarchy Hard to meet the bandwidth demand and flexibility required between some edge routers

Layer 3 Bypass Models Shifting the Capex budget out of (more expensive) IP equipment towards (lower cost) optical equipment Bypass options: At L2 (Lean Core):

55 Layer 3 Bypass Models Shifting the Capex budget out of (more expensive) IP equipment towards (lower cost) optical equipment Bypass options: At L2 (Lean Core): MPLS LSR At L1: OTN switching At L0: photonic bypass Partial vs full bypass (Hollow Core) Layer 3 Layer 2 Layer 1 Layer 0 Bypass at L2 Bypass at L1 Bypass at L0

56 How to Use Layer 3 Bypass Hierarchical routing for small flows Lean core (bypass at L2) in hierarchical design OTN bypass (at L1) if a variety of flows going to different directions and intermediate flows DWDM bypass (at L0) for large flows Be cautious with full bypass

57 Integrated Multilayer Systems Admin VM Control Plane VM Linecard VM OS Virtualization / Hypervisor Agnostic Fabric SONET/SDH OTN MPLS Ethernet IP DWDM NCS 4000

58 Multilayer Control Plane IP (Client) Peer Model Overlay Model UNI UNI WDM (Server) Peer Model: same domain, same topology Overlay Model: UNI, separate topologies; client can request circuit setup and teardown

59 Cisco nlight Control Plane nlight extends GMPLS UNI with circuit attribute information exchange Circuit established per requirements Server may inform Circuit-ID SRLG s along the circuit Path latency Information refresh Server topology/resource Server policy control Client may request SRLG s to be excluded or included Path to follow another Circuit-ID Path to be disjoint from another Circuit-ID Optimization upon shortest latency Bound on latency not to exceed Optimization upon lowest optical cost Optical restoration Optical re-optimization

60 Bandwidth On Demand IP (Client) UNI-C 6. Informs UNI-C WDM (Server) UNI-N 1. Signals a circuit to egress UNI-C NNI 3. Signals the path 5. Sets up return path NNI UNI-N UNI-C 2. Performs path calculation to find egress NNI and UNI-N 4. Performs impairment calculations

61 Multilayer Protection and Restoration Multiple layers of routing options OTN/DWDM Protection: predesignated facility for fast switchover (< 50 ms) Router Link Fast Reroute: fast switchover (< 50 ms) OTN/DWDM Restoration: dynamic switchover for second level of service restoration (seconds to minutes) Layer 3 reroute

62 Multilayer Network Optimization Collection Topology Circuits Resources Analysis Impact Analysis What if Scenarios Restoration feasibility Optimization Coordinated Maintenance Feasibility IP/MPLS' Service' GMPLS' WSON' Network Op miza on Server Network Collec on / Deployment Plug-Ins Service' Packet' OTN' Configuration Packet'NE' OTN'NE' DWDM'NE' DWDM'

63 Multilayer Orchestration Architecture Application North Bound APIs Service Management Functions Inventory Base Network Management Functions Topology Config Fault Assurance SW Mgmt Platform Base Services Functions DB Device Access Functions Protocol Abstraction Layer SNMP OpenFlow HTTP/XML Netconf Network Elements

Use Cases of Service Automation Network deployment automation Turn-up configuration Post-deployment connectivity verification Service provisioning automation

64 Use Cases of Service Automation Network deployment automation Turn-up configuration Post-deployment connectivity verification Service provisioning automation Service optimization Bandwidth calendaring Operational automation DWDM power check Software image management and upgrade Network fault remediation Operational analytics

65 Challenges and Solutions Reputation Cost Profitability Integrated systems Flexible Layer 3 bypass ODU grooming Packet transport Agile DWDM layer Multilayer control plane Multilayer orchestration Converged layers Risk Success Experience Growth 100G and beyond High channel count Super channels Multi-degree ROADMs

66 The Provider Dollar Gap Exponential Traffic Growth Declining Revenue per bit

A Winning Strategy Preserve What Is Working Resiliency Scale Rich feature set Evolve for Emerging Requirements + Automation = Convergence Virtualization

67 A Winning Strategy Preserve What Is Working Resiliency Scale Rich feature set Evolve for Emerging Requirements + Automation = Convergence Virtualization Application interaction Achieve Business Objectives Service agility and velocity Simplified operations Higher value services Evolved Programmable Networks

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1 COPYRIGHT 2013 ALCATEL-LUCENT. ALL RIGHTS RESERVED.

1 COPYRIGHT 2013 ALCATEL-LUCENT. ALL RIGHTS RESERVED. 1 The Road Towards Packet Optical Transport Networks: Optical Transport Networks Evolution to OTN/DWDM Gil Bento Alcatel-Lucent April 9 th ISCTE-IUL 2 AGENDA 1. BANDWIDTH DRIVERS 2. OPTICAL TRANSPORT NETWORK