SDN Architecture and Standards for Operational, at Scale Networks. 신명기 ETRI KRNET June 2012

Transcription

1 SDN Architecture and Standards for Operational, at Scale Networks 신명기 ETRI KRNET June

2 Content Outline SDN Framework and Architecture Data Forwarding Plane Models Open Interfaces for Control Planes Standardization Activities ONF IETF/IRTF ITU-T SDN Deployment Issues Summary and Next Steps 2

3 Software-Defined Networking Definition & objectives A networking technology which allows programmable control planes so that network operators and application/service providers can control and manage their own virtualized slices A layer on top of infrastructure which provides service discovery/composition, network provisioning, topology gathering, and monitoring, etc. Incremental and fast deployment There may exist many mechanisms to realize SDN OpenFlow may be one of mechanisms, architecturally IETF protocols (L2/L3 VPN, MPLS-TE, I2AEX, etc.) Use cases Data center, Enterprise networks, Home networks, etc. 3

4 (Techs) Today s Network vs. SDN Control Plane Network OS Data Plane (Specialized Hardware) Separation Control Plane Network OS Data Plane (Specialized Hardware) Controller (Software) Abstract Network Model (Open API, Script, Language) Client Dumb Pipe Network Operators Contents Server (e.g.,) OpenFlow protocol Smart Pipe Content Providers Client Network Operators Contents Server Data Routing Mobility A Single Physical Infrastructure Energy efficient forwarding 4

5 (Ecosystem) Today s Network 3 rd Parties Mac, Windows Apps OS Commodity Hardware Computers Specialized Features + OS + Hardware Networks Cisco, Juniper Huawei.. Closed, proprietary 5

6 (Ecosystem) SDN s Perspective (esp. service providers) Apps Network Apps 3 rd Parties 3 rd Parties Mac, Windows OS Network OS Nicira, Big Switch.. Commodity Hardware Computers Commodity Hardware Networks Open VSwitch.. Open Interfaces 6

7 OpenFlow vs. SDN OpenFlow Open Interfaces between data and control plane SDN SDN abstractions, object models, a set of APIs OF is (just) one of architectural components of SDN Ecosystem for new features, new players, new business models 7

8 SDN Framework Framework for software-defined networking, including Separation of control and data planes Controller, NetworkOS, etc. Programmable control plane through network abstraction (e.g., language, libraries, etc.) Packet Forwarding Hardware (e.g., commodity hardware) Open interfaces for control plane OpenFlow IETF RFCs and others (L2/L3 VPN, MPLS-TE, etc.) Map into virtualization of the underlying networks 8

9 SDN Architecture SDN Services, Apps Northbound Interface SDN Language App APIs East-west Interface Carriers Infrastructure Information E.g., ALTO, Monitoring, management Programmable Control Plane Network OS Southbound Interface Programmable Control Plane Network OS E.g., OF, L2/L3 VPN, MPLS-TE, etc. Control and Data Planes Separation Data Plane (Forwarding Hardware) Data Plane (Forwarding Hardware) Data Plane (Forwarding Hardware) Data Plane (Forwarding Hardware) 9

10 SDN Data Forwarding Forwarding Plane Models (proposed by ONF FPMODS WG) OpenFlow 1.0 Forwarding Element Constrained OpenFlow 1.1 Forwarding Element Ethernet Device Stateless Generic Tunnel Encap/Decap Element Stateful Generic Tunnel Encap/Decap Element Layer 3 IPv4 Forwarding Element Layer 3 IPv6 Forwarding Element Dual stack (v4 + v6) Forwarding Element Will be designed and developed more, hopefully Optical/circuit, wireless, etc. 10

11 SDN Control Interfaces (1/3) Southbound Interface Programmability and quick re-configurability Sharing of resources (network, computing) Traffic Isolation Network abstraction (e.g., data forwarding) 11

12 Southbound APIs OF 1.0 (03/2010) Most widely used version, MAC, IPv4, single table OF 1.1 (02/2011) MPLS tags/tunnel, multiple tables, counters OF 1.2 (12/2011) Wire protocol, IPv6, basic configuration, extensible expression OF 1.3 (04/2012) Topology discovery, test processes, test suites OF 1.4 (08/2012) Capability discovery, test labs. OF Future (2.0) Modularity and extensibility (New forwarding models, FPMODS) 12

13 SDN Control Interfaces (2/3) Northbound Interface Routing-related; Topology discovery, traffic engineering, etc. Delay, jitter, QoS, etc. Management-related; Resource, energy use, etc. Monitoring, maintenance, etc. accounting, etc. Policy-related; Access control, security, etc. 13

14 Northbound APIs Potential APIs Media streaming network setup (video conferencing, live transmissions, etc.) VPN management Content distribution control Network management & orchestration Compare to Computer OSs Each apps would like to have its own specific Northbound API?? Source : Northbound API / SDN API discussion (ONF, 2012) 14

15 SDN Control Interfaces (3/3) East-west Interface Intra-domain? inter-domain? Scalability Interoperability Deployability 15

16 East-west APIs Controller internal APIs? topology (discovery) packet-in access path computation switching table access Source : Northbound API / SDN API discussion (ONF, 2012) 16

17 SDN Standards ONF (Open Networking Foundations) OF 1.3.x OF-Config 1.1 IETF/IRTF IETF SDN Bof IRTF SDNRG (Proposed) ITU-T Y.FNsdn (SDN framework) Y.FNsdn-fm (SDN formal specification and verification) 17

18 ONF s Standardization - WGs Extensibility (chair: Jean Tourrilhes, HP) Maintains the core of the OpenFlow switch specification Extensible match & error messages, wire protocol, forwarding model, MAC, IPv4, IPv6 Config-mgmt (chair: Deepak Bansal, Microsoft) Defines mechanisms for configuration of openflow capable network devices to realize the vision of Software Defined Networking Protocol & schema for basic config, single logical switch to main/backup controller Testing interop (chair: Michael Haugh, Ixia) Conformance test suites, performance benchmarking, interoperability plug tests Hybrid programmable Forwarding Plane (chair : Bruce Davie, Cisco Systems) Forwarding Plane Models WG (Proposed) Architecture/Framework WG (?) Source

19 IETF SDN BoF Defined Software/applications and interfaces whose sole purpose is to control a network's data plane Driven A software/applications interface for providing a network's control plane with the data plane (service) requirements and for receiving feedback on the service/treatment being delivered 19

20 IRTF SDNRG (Proposed) Areas of Interest Include: Hybrid models Classification of SDN models and their relationship to existing IETF work SDN model scalability and applicability Multi-layer programmability and feedback control systems System Complexity Network description languages, abstractions and APIs Much longer-term research goals 20

21 SDN Work Items in ITU-T Q.21 of SG13 (Future networks) Studying networks of future networks Has identified network virtualization as important components of telecom networks Hopes to be the pivot of SDN discussion in ITU-T Draft Recommendations in Q.21 Y.FNsdn, Framework of software-defined networking for Future Networks (Q1 2013) Y.FNsdn-fm, Requirements of formal specification and verification methods for software-defined networking (Q4 2013) More groups will join in the future There is a group to include QoS in SDN in its scope Probably more in the future (e.g., cloud computing groups) (Nov 2012: regular reorganization of every four years) 21

22 ITU-T Y.FNsdn The scope of this Recommendation covers: Definition and overview of software-defined networking Attributes of softwaredefined networking Architecture for softwaredefined networking, including Use cases of softwaredefined networking as an informational part Map into OpenFlow, L2/L3 VPN, MPLS, or Virtualization,etc, Client Data Routing Programmable Control plane Network abstraction Open Interface NEs Mobility Virtualized Programmable Infrastructure Network Operators Content Server Energy efficient forwarding 22

23 SDN : Deployment Issues Scalability (EW APIs) A single controller : a single point of failure Inter-domain issues Interoperability (EW APIs) Multi-controllers, multi-operators, etc. Policy-related Security Controllers attacked Malicious controllers destroy whole networks Validation and verification Monitoring and Management (NB APIs) Hybrid Switch Incremental Deployment with ALTO 23

24 SDN : Carriers Issues Optical extensions to OF/SDN Wireless integration, characterization of wireless interfaces, flows, handover support Evolved packet core, LTE support for OpenFlow New controller architectures, API, SDN north-bound interfaces Higher level SDN abstractions, APIs, object models CCN/ICN and their relation with SDN Carrier-grade SDN architectures and equipment Network Virtualization techniques based on SDN SDN frameworks and tools, testing, and debugging 24

25 Formal Specification and Verification Why Formally Verifiable Framework in SDN? Incomplete or malicious programmable entities could cause break-down of underlying networks shared by heterogeneous devices and stake-holders. Formally verifiable networking framework for SDN Formal specification, Verification methods, and Implementation 25

26 Formal Specification / ACSR Example 0. Design abstract network model using Informal specification (e.g., virtual network topology, etc.) Switch 1. Formal Specification H1 H2 H3 2. Verification Methods Model Checking Theorem Proving Invariant Checker.. Network = (H1 H2 H3 Switch) \{inport,outport1,outport2,activatingrule1, activatingrule2,activatingrule3};.. 3. Implementation (Control Software) SDN Data plane (heterogeneous devices, switches, etc.) FlowTable(r1,r2,r3) = (r1 = 1) -> (rule1?,4).(action1!,99).flowtable(r1,r2,r3) + (r2 = 1) -> (rule2?,3).(action2!,99).flowtable(r1,r2,r3) + (r3 = 1) -> (rule3?,6).(action3!,99).flowtable(r1,r2,r3) + (activatingrule1?,99).flowtable(1,r2,r3) + (activatingrule2?,99).flowtable(r1,1,r3) + (activatingrule3?,99).flowtable(r1,r2,1); + (rule0?packet,0).('requestruleforpacket?packet,99). FlowTable(r1,r2,r3); 26

27 OpenFlow-Hybrid Switch Why Hybrid? Scale OF Controller Maintain Layering and Simplify Services not related to forwarding ONF Hybrid WG Activities Hybrid Data-Plane Port-based Partitioning VLAN-Based Partitioning Flow-Based Partitioning Hybrid On-Board Control Planes Hybrid Off-Board Control Planes 27

28 OpenFlow-Hybrid Switch Source : Hybrid Switch WG, ONF 28

29 IETF ALTO Application Layer Traffic Optimization App Area Transport Area (2011) Better-than-random resource provider selection Network Topology (network and cost maps) Very application friendly (HTTP+REST+JSON) Easily extensible Use Cases P2P apps Almost DONE!! 29

30 I2AEX (Infra-to-App Extension) Distributed applications get smarter Enabling infrastructures to expose useful information ALTO extensions Info types: Network load Resource availability (CPU, storage, etc.) Content availability Server- to- client notifications Incremental updates Focus restriction: fully and partially controlled env. Use cases : CDN, datacenter apps, SDN 30

31 SDN with ALTO? Applications / infrastructure deployed with SDNs Limited to a single administrative domain which could consist of multiple SDN domains ALTO-SDN generalizes ALTO-CDN / ALTO-DC Use cases : (inter or intra-sdn domains) SDN On-Demand Bandwidth SDN-Aware QoS Bulk Data Transfer Source Tina Tsou 31

32 SDN with ALTO? I2AEX ALTO collects coarse-grain information from SDN domains Granularity depends on I2AEX policies defined by individual SDN domains Info type: e.g., bandwidth, connectivity, cost, etc. Source Tina Tsou

33 SDN-ALTO-Deployment ALTO(I2AEX) Server ALTO Client SDN Controller-A (NetworkOS) ALTO Client SDN Controller-B (NetworkOS) X-Routing X-Routing SDN Domain-A ALTO provisioning ALTO provisioning SDN Domain-B OpenFlow OpenFlow OpenFlow non-of domains OpenFlow OpenFlow OpenFlow 33

34 Summary and Next steps CAPEX/OPEX reduction Easy management (Reduce network complexity) Smart routing and quick re-configurability Incremental deployment Flexible networks (multiple isolated networks) Commodity Switch (HW) market vs. Controller/NetworkOS (SW) market Carriers vs. Service providers perspectives 34