WIXLIB

SDN in SP WANTECH-SDN-SPDavid JaklSystems Engineer

Agenda SDN in SP WANMulti-Layer SDNPCEPBGP Link StateBGP FlowspecSegment RoutingSummary

SDN enables IP/MPLS evolution to a hybrid control-planecentralized control improves network operations and plicationsControllerEvolution Distributed Control remains best for many use-cases; e.g. IGP convergence Centralized Control introduces new value; e.g. TE placement optimization4

SDN WAN Transport – Use CasesOptimization Global Load Balancing Multi Layer Optimization Coordinated Maintenance LSP splitting and merging Network Rearranging Segment RoutingMonetization Bandwidth Calendaring with Hybrid Cloud Premium Bandwidth Path Diversity Latency Based Forwarding5

hourlydailyweeklymonthlyquarterannualTraffic change frequencyAnother Perspective of Offline vs Online SDN WANOrchestrationSDN WAN(online)Planning(offline)25%50%Load / Link75%100% When the planning inputs change almost on a hourly basis and the networkload is close to the max-link-load objectiveSource: Clarence Filsfils6

Our SDN WAN Orchestration Platform Evolving AppsNB APIOrchestrationOptimization orDeployerIPv4/IPv6/MPLSSegment RoutingOptical7

SDN WAN Orch Use-Case #5: Maintenance Window Scheduling243OpsNB APISDN WAN OrchCollector1DeployerPCEPWAN5① Network conditions reported tocollector② Ops selects Ra, Rb and maintwindow time③ Maint Window request: Ra, Rb, Window ④ SDN W-O returns impact andchangeover plan. Ops confirms⑤ At Maint Win start SDN W-O rearranges traffic to bypass Ra, RbR2R1CustomersRaRbR3DC/Clouds8

The Multi-Layer Optimization – nLight The new DWDM layer enables a truly Converged IP Optical Transport Scalable more than 8Tb/s per fiber, based on 100 Gb/s DWDM channels Flexible, fully non-blocking wavelength switchingBUT – Past: Optical BW was relatively cheap throw optical BW at the problem– Future: Optical BW most expensive part of CapEx need to use it efficiently SDN transport enables Converged network optimization– SLA aware routing (e.g. min Latency) or Cost aware routing (e.g. min regens)– Link failure Restoration can lead to 20 % savings, by reusing available router ports SDN innovation most important for Converged Transport The IP/MPLS evolution to SDN is an important innovation!SDNController(WAN O) Optical control, always mainly centrally controlled (NMS)!9

Multi-Layer IP/Optical PCE Models (Examples) Single-Layer PCE– Visibility into L3 and opticaltopologies– Programs L3 and L3 UNI tooptical Separate PCE– Operates on each layer– Optional inter-layer PCEcommunicationsVNT M Virtual Network T opology Manager10

SDN WAN Use-Case #9: SDN WAN Orch TriggeredGMPLS Setup① Realtime data collectionreveals trending congestion(Rc-Rb link) imminent② Ops App requests Multi-layeroptimization③ SDN W-O programs Ra and Rbto initiate GMPLS Setup④ New Ra-Rb link is injected intoIP/MPLS TopologyML PathOptimization App21NB APIOpsSDN WAN OrchCollectorDeployerPCEP3RcCongested!!4R1RaGMPLS UNIO1RbGMPLS UNIR2O211

PCEPBGP Link StateBFP Flowspec12

PCE Architecture Addresses complex requirements for path computation in large, multi-domain and multi-layer networks Path computation element (PCE)–Computes network paths based on network information (topology, paths, etc.)–Stores TE topology database (synchronized with network)–May reside on a network node or on out-of-network server–May initiate path creation–Stateful - stores path database included resources used (synchronized with network)–Stateless - no knowledge of previously established pathsHELLOmy name isPCE Path computation client (PCC)–May send path computation requests to PCE–May send path state updates to PCE PCC and PCE communicate via Path Computation Element Protocol (PCEP) Cisco innovation, standardization started in 2005 First implementation (stateless PCC/PCE on network nodes) released in IOS XR 3.5.2 for inter-area TE Cisco WAN orchestration provides network path instantiation driven by an out-of-network stateful PCE13

Stateful PCEStateful PCE Introduces PCEP extensions forLSP DB– LSP state synchronization betw een PCCs and PCEs– PCC delegation of LSP control to PCETED Passive stateful PCE– PCC maintains state synchronization w ith PCE– PCC exclusively controls LSP– PCE does not modify LSP statePCEP Active stateful PCE– PCC maintains state synchronization w ith PCE– PCC may delegate LSP control to PCE Either PCE or PCC can initiate LSP setupPCCPCE-initiatedLSP PCC always owns LSP state Cisco WAN orchestration solution relies on an active stateful PCE that initiates LSP setup14

BGP Link State BGP may be used to advertise link state andlink state TE database of a network (BGPLS) Provides a familiar operational model toeasily aggregate topology information acrossdomains New link-state address family Support for distribution of OSPF and IS-ISlink state databases Topology information distributed from IGPinto BGP (only if changed) Support introduced in IOS XR 5.1.1 draft-ietf-idr-ls-distribution15

BGP Flowspecfor SDN WAN Orchestration Define classification and action semantics inBGP called Flow Specifications (Flowspec) Leverage BGP control plane and transportfor efficient, scalable flowspecannouncements and withdrawls Enhanced actions:––––Traffic-rateTraffic-action (includes sampling, logging)Redirect (NH, VRF)Traffic-marking (DSCP) RFC 5575 IOS XR 5.2.016

OffRamp in “Dirty” VRF: How FlowSpec helps?More granular, only the protocol/port/packet-size is diverted in Dirty VRF Simple and scalableVRF dirty0.0.0.0/0nh: @TMSBGP FSMatch: dest-IP: 2.1.1.1 dest-port: 80Action: NH: VRF Dirty@TMSJSRRIPv4Match: dest-IP: 2.1.1.1I dest-port: 80Action: NH: VRF DirtyFVictim2.1.1.1LHECKGDBMVRF dirty0.0.0.0/0nh: @TMSstaticBGP FSControllerstatic A

Segment Routing18

Balance of Distribution and CentralizationDistribution-onlyRSVP-TENon-optimum, non-predictable,and experienced as too Deployability within18months?

MuchMore !Confirmed Operators: Orange, Facebook, Google, Telstra,Goldman, BT, Belgacom, TW, Comcast, Liberty, SFR Interested Operators: DT, TI, Telefonica, Cox, Century Link,One-yearReuters, Barclays, Sky Ciscofirst-publicpresentationDC2WANbirth daydemoSR/TE firstpublic demoConfirmed use-cases: SDN/TE, FRR,presentsEPE, DC,service integration, Access/MetroE TI-LFA w ithXR andCisco NAGOperatorGroupFormedOct12CiscoCiscoreleases apresents SRXEroadmap total of 8 IETFat MPLS WCdrafts on SRw ith demoCiscoreleases 2IETF draftson SR12 IETF draftsSPRING WGJNPR j oinsMore !15 IETF draftsFCS SWALU/Ericssonj oinMar13Jul13Nov 13Mar14Jul14Nov 14www.segment-routing.net

Nodal segment to CNodal segment to CABCDAdj SegmentMNOZPNodal segment to Z Simple extension to IS-IS or OSPF, automatically builds and maintains SegmentsNodal Segment – A Shortest path to the related nodeAdjacency Segment – One hop through the related adjacency Excellent Scale: a node installs N A FIB entriesN nodal segments; A adjacency segments21

FEC Zpush 65Aswap 65to 65swap 65to 65Bpop 65CDZPacket to Z656565Packet to ZPacket to ZPacket to Z65Packet to ZA packet injected anywherewith top label 65 will reach Zvia shortest-path Node Z advertises its node segment (loopback 0)e.g. in ISIS its just a simple ISIS sub-TLV extension All remote nodes install the node segment to Z in the MPLS dataplane22

ABCDPop9003MNOZPA packet injected at node Cwith label 9003 is forcedthrough datalink CO Node C allocates a local label for CO link segment C advertises the adjacency label in IGPe.g. for ISIS, it’s a simple sub-TLV extension C is the only node to install the adjacency segment in MPLS dataplane (FIB)23

Source Routing along with the explicitpath, stack of nodal and adjacencysegments Any explicit path can be expressed:e.g. ABCOPZ7272900390039003656565Packet toZPacket toZPacket toZ72 ECMPNode segmentA72BCD9003Z Per-flow state only at head-endnot at midpoints Source Routingthe path state is in the packet headerMNOP65Packet to Z656565Packet to ZPacket toZ24

ABPE2PE1MNAll VPN services ride on the node segmentto PE2IPv4 over MPLS/IGPVPN over MPLS/IGPInternet over MPLS/IGPPW over MPLS/IGPIPv6 over MPLS/IGP Efficient packet networks leverage ecmp-aware shortest-path!node segment! Simplicityno complex LDP/ISIS synchronization to troubleshootone less protocol to operate25

PEPEPEPEPEPEPPE SR router scales much more than with RSVP-TEThe state is not in the router but in the packetNode Adj vs. Node 2 No requirement of RSVP-TE protocolAnd knobs such as LDPoRSVP etc.NodeSegmentIdsAdjacencySegmentIdsPEIn LabelOut LabelOutInter faceL1L1Intf1L2L2Intf1 L8L9 L8Pop Intf4Intf2L10PopIntf2 LnPopIntf5FIBremainsconstant26

draft-francois-segment-routing-ti-lfa Guaranteed Link/Node FRR in any topologyBackboneeven w ith asymmetric metrics No Directed LDP sessionC1 SimplicityC2entirely automated (no need for customization) Incremental deploymentE1E4Applicable to LDP and IP primary trafficOnly the repair tunnel is SR-based For networks with symmetric metric & link protectionNo extra computationSimple repair stack1000E2E3Node segmentto P nodeAdj segmentto Q nodeNode segment to P nodeAdjacency segment from P to Q Demo availableDefault metric: 1027

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SR with WAN Orchestration WAN O allows for the best possible simplification of SR– Optimum state computation– A single touch-point at the Source Node– Instant set-up timeAsk for path to Gw ith certain SLA(delay, bandw idth,duration, etc) Also a stateful PCE, as with MPLS-TE, can be help to:– Compute globally optimum paths for traffic-engineered SR tunnels1B– Instantiate SR tunnels based on requests from applications– Instantiate traffic steering onto the instantiated tunnelF0DCGEA Minimal changes–––––PCEP capability to negotiate SR between PCE and PCCIGP capability used by PCE’s to advertise their SR/PCE capabilityExtension to BGP-LS to convey the segmentsExtension to IR2S policy retrieval to include segment informationMinimal changes in (Cisco) CLI and look and feel stays sameSDN WAN OIndentify bestpath andsegments (B, D,C, E, G)29

Summary30

Summary SDN WANPCEPBGP Link StateBGP FlowspecSegment Routing

Technology ObjectivesConfigurable NetworksOrchestrated NetworksApps-aware NetworksNetwork-aware AppsNetwork InterfacesProgrammatic Interfaces (& Overlays)Simplify NetworksSegment Routing,IP Optical ConvergenceM ake everything go faster, easier and more agile32

Scenario 1: Using ECMPScenario 2: Using One Path ofECMPScenario 3: Using AnycastSegmentScenario 4: Not UsingShortest PathScenario 5: Traversing Links

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SDN enables IP/MPLS evolution to a hybrid control-plane centralized control improves network operations and optimization Applications Applications Controller Evolution Applications Distributed Control remains best for many use-cases; e.g. IGP convergence Centralized Control introduces new value; e.g. TE placement optimization 4