1. 國立清華大學高速通訊與計算實驗室 NTHU High-Speed Communication & Computing Laboratory A Hot Topic in Computer Networks Today: Software- Defined Networking Prof. Jang-ping Sheu High-Speed Communication & Computing Laboratory National Tsing Hua University

2. Outline  Background and motivation  What is SDN ?  An open standard- OpenFlow  The applications of SDN  Challenges  Research resources 2

3. Outline  Background and motivation  What is SDN ?  An open standard - OpenFlow  The applications of SDN  Challenges  Research resources 3

4. Internet in Recent Decade Data increasing continuously: Data Center, Cloud Computing, and Big Data E-business, Video on demand, MOOCs (Massive Open Online Courses) More protocols created with Heterogeneity networks developing VANET (Vehicular Ad-hoc NETwork), WSN (Wireless Sensor Network), CRN (Cognitive Radio Network) 4

5. 5 Source: Intel 2012 March

6. Traditional Networks - Features Closed equipment Software bundled with hardware Vendor-specific interface Only vendors can develop for its constrained environments Over specified Various and complex protocols: OSPF, BGP, DiffServ, NAT, MPLS, and so on. No uniform standardization Buggy software in the equipment Routers are with million of lines of source code Cascading failures, vulnerabilities is popular 6

7. Traditional Networks - inconvenience Operating a network is too complex and expensive To add or move any device, network must be reconfigured, such as router, switch and firewall Too expensive to change the topology of network Not easy to control the communications User cannot write the control code except equipment vendors Long delays to introduce new features Difficult to customize: Even vendors and third parties are not able to provide customized cost effective solutions to address their customers’ problems 7

8. Million of lines of source code 6,000 RFCs （ Request For Comments ） Billions of gates, Bloated,Power Hungry Vertically integrated, complex, closed, proprietary Not suitable for experimental ideas Specialized Packet Forwarding Hardware Operating System Operating System Feature Routing, management, mobility management, access control, VPNs, … We Need Modify Existing Equipment Switch 8

9. Vertically integrated Closed, proprietary Slow innovation Small industry Specialized Operating System Specialized Operating System Specialized Hardware Specialized Hardware App Specialized Applications Specialized Applications Horizontal Open interfaces Rapid innovation Huge industry Microprocessor Open Interface Linux Mac OS Mac OS Windows (OS) Windows (OS) or Open Interface 9

10. Vertically integrated Closed, proprietary Slow innovation App Horizontal Open interfaces Rapid innovation Control Plane Control Plane Control Plane Control Plane Control Plane Control Plane or Open Interface Specialized Control Plane Specialized Control Plane Specialized Hardware Specialized Hardware Specialized Features Specialized Features Merchant Switching Chips Merchant Switching Chips Open Interface 10

11. Outline  Background and motivation  What is SDN ?  An open standard- OpenFlow  The applications of SDN  Challenges  Research resources 11

12. Software-Defined Networking (SDN) SDN is an approach to networking in which control is decoupled from hardware and given to a software application called a controller Allows network engineers to support a switching fabric across multi-vendor hardware and application- specific integrated circuit Allows a stronger intellectual foundation to networking Allows us to define the right abstractions in different layers Allows us to transfer technology much faster, in both directions (academic and Industry) Closing the gap with industry 12

13. SDN from Traditional Network Device 13 Ethernet Switch

14. 14 Data Path (Hardware) Controller (Software) SDN from Traditional Network Device

15. 15 Data Path (Hardware) Control Path OpenFlow OpenFlow Protocol (SSL) Controller SDN from Traditional Network Device

16. 16 OpenFlow Protocol (SSL) Controller Ethernet Switch SDN from Traditional Network Device

17. More Detail in SDN Specialized Packet Forwarding Hardware App Specialized Packet Forwarding Hardware App Specialized Packet Forwarding Hardware App Specialized Packet Forwarding Hardware App Specialized Packet Forwarding Hardware Operating System Operating System Operating System Operating System Operating System Operating System Operating System Operating System Operating System Operating System App Network Operating System Control Programs 17

18. More Detail in SDN Simple Packet Forwarding Hardware Network Operating System Control Programs 18

19. Packets Delivering in SDN 19 Controller PC OpenFlow Switch User’s code Decision? OpenFlow Protocol User’s Rule

20. Potential Application Model in SDN Data Centers Public and private clouds WANs Google WAN Eventually, public WANs Enterprise networks Greater control, fewer middle boxes Home networks Outsourced management Cellular Networks Separation of service from physical infrastructure Research and Education Networks National backbones College campus networks 20

21. Outline  Background and motivation  What is SDN ?  An open standard- OpenFlow  The applications of SDN  Challenges  Research resource 21

22. OpenFlow - What is it ? An open standard for that enables researchers to run experimental protocols in the campus networks we use every day Network administrators can remotely control forwarding tables by it Currently being implemented by major vendors Enabled switches now commercially available 22

23. OpenFlow Controller OpenFlow Switch Flow Table Flow Table Secure Channel Secure Channel PC OpenFlow Protocol SSL HW SW 23

24. OpenFlow - Controller A controller adds and removes flow entries from the Flow Table on behalf of experiments A static controller might be a generalization of VLANs. More sophisticated controllers that dynamically add/remove flows as an experiment progresses Researchers might control the complete network of OpenFlow Switches and be free to decide how all flows are processed 24

25. OpenFlow - Switch Flow Table, with an action associated with each flow entry, to tell the switch how to process the flow Secure Channel that connects the switch to controller, allowing commands and packets to be sent between a controller and the switch OpenFlow Protocol, which provides an open and standard way for a controller to communicate with a switch 25

26. OpenFlow - Flow Table Entry Switch Port MAC src MAC dst Eth type VLAN ID IP Src IP Dst IP Prot TCP sport TCP dport RuleActionStats 1.Forward packet to port(s) 2.Encapsulate and forward to controller 3.Drop packet 4.Send to normal processing pipeline Packet + byte counters 26

27. OpenFlow - Cache flow decisions in datapath “If header = x, send to port 4” “If header = ?, send to me” “If header = y, overwrite header with z, send to ports 5,6” Flow Table Flow Table 27

28. Deployment Modes In-network: OpenFlow-enabled network infrastructure (upgraded or green-field) Overlay: Legacy network infrastructure with smart edge devices New boxes, such as gateways Enhanced kernel bridge (e.g., OpenVSwitch in x86 hypervisors) Examples: In-network: Google uses OpenFlow-enabled controllers switches to interconnect their data centers Overlay: AT&T, NTT, eBay, Fidelity Investments, and Rackspace use OpenStack Quantum and Nicira NVP controller to manage the virtual networks in their clouds Hybrid: Genesis hosting uses NEC controller in intra-data-center scenario 28

29. Outline  Background and motivation  What is SDN ?  An open standard - OpenFlow  The applications of SDN  Challenges  Research resource 29

30. Benefits from SDN Network Virtualization Switch based Firewall Multipath Forwarding Congestion Control Identify bugs 30

31. Network Virtualization in SDN The process of combining hardware and software network resources to be some virtual networks 31

32. Virtualization in Traditional Network L2 virtualization: VLAN Networks can only support a finite number of VLANS 32

33. SDN-based Network Virtualization Each tenant can run his virtual network with controller in SDN. OpenFlow network removes limitations, allowing administrators to create a flow-based virtual network abstraction. 33 Computer virtualization Network Virtualization

34. SDN-based Network Virtualization 34

35. Switch based Firewall in SDN OpenFlow switches can emulate Firewall by assigning rules to switches. 35 Controller H1 H2 H3 Flow Classifer Cloud Block this flow This packet needs to block

36. Traditional Switch Path Forwarding In traditional switches, forwarding packets use spanning tree algorithm to solve looping problem 36

37. Multipath Forwarding in SDN Forwarding by rule and central controller’s decision. 37 Controller

38. Congestion Control by SDN Controller can get SDN switches information to know if congestion happened. 38 ControllerController gets switches status to decide flow rate

39. Identify Bugs by SDN Identify bugs with systematically tracking down their root cause When an operational network misbehaves, it is very hard to find the root cause Allows users to define a Network Breakpoint Capture and reconstruct the sequence of events leading to the breakpoint 39

40. Outline  Background and motivation  What is SDN ?  An open standard - OpenFlow  The applications of SDN  Challenges  Research resource 40

41. Countries in Trial of SDN 68 Trials in 13 Countries 41

42. SDN in University of U.S.A Severing as GENI (Global Environment for Network Innovations) Networking Substrate 42

43. Challenges Complex designing solutions Limited TCAM size Controller delay and overhead Multi-controller working together Migrating from legacy to SDN 43

44. SDN - Data-Plane Challenges State of Specification Maturity Concerns OF 1.0 single flow table, … OF 1.1 leverages multiple tables Silicon Concerns Spec is much ahead of silicon development… OF Spec is a moving target for merchant silicon Merchant silicon is not optimized for OF… supports of current networking features is a higher priority Specific issues Scalability of Flow-Matches (limited by TCAM size) Cost concerns 44

45. SDN – Control-Plane Challenges Control Plane scalability Centralized vs. distributed controllers... Single view of the state of the network, forwarding tables,… is this a distributed database problem? Interoperability SDN/NON-SDN Inter-Controller Between different controllers Orchestrating SDNs managed by different controllers … 45

46. SDN - Application-Environments Challenges Network Resource Abstraction & Conflict Resolution Resource abstraction Conflict resolution among different application actions Development tools and New Application Paradigm Computing system style application… New class of Network Programming Languages… New tools New development skills… New talents... New education curriculum… 46

47. Outline  Background and motivation  What is SDN ?  An open standard - OpenFlow  The applications of SDN  Challenges  Research resources 47

48. Research Platform for SDN Mininet Network emulator Designed for emulating SDN networks Easy to use High performance (100 nodes on a laptop) Network OS for Research NOX (C++/Python) http://noxrepo.orghttp://noxrepo.org Maestro (Rice University) Helios (NEC) Beacon (Java) coming soon, … Network OS Commerce ONIX [OSDI 2010, Google, Nicira, NEC] Expect others 48

49. OpenFlow Testbed Candidate controllers: Nicira’s Nox: C++ and python  prototyping NTT’s Ryu : python  more production level Candidate switches: Standalone switches Pica8 (3290): OpenFlow v1.1, a spin-off of Quanta HP (5400zl): either OpenFlow mode or legacy mode. NEC(IP8800): either OpenFlow mode or legacy mode. Pronto: legacy routing stack and OpenFlow enabled features can not be support in the same VLAN Brocade (CES/CER/MLX/XMR/MLXe): fully support hybrid mode PC-based switches (decreasing programmability) OVS (OpenVSwitch): pure software based OpenFlow enabled data path Netronome: network processor PCI card NetFPGA (Stanford): research oriented cards 49

50. Thank you ! 2011I International Conference on Computer Science an d Network Technology 50