Brandon Schlinker University of Southern California, California, USA Research Track Session Part 1 ONS2015: http://bit.ly/ons2015sd ONS Inspire! Webinars: http://bit.ly/oiw-sd Watch the talk (video) on ONS Content Archives: http://bit.ly/ons-archives-sd

3. Try Before you Buy:
SDN Emulation with (Real) Interdomain Routing
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Brandon Schlinker⋆, Kyriakos Zarifis*, Italo Cunha♮, Nick Feamster †,
Ethan Katz-Bassett*, and Minlan Yu*
University of Southern California, California, USA⋆
Universidade Federal de Minas Gerais, Minas Gerais, Brazil♮
Georgia Institute of Technology, Georgia, USA†
Open Networking Summit
Santa Clara, California, USA
March 2014

4. SDN Presents New Questions for Network Operators
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Questions in Legacy Networks:
 Protocol(s) to Use
 Internal Routing (IGPs: OSPF, RIP)
 Scalability
 BGP scalability
 Equipment Vendor
 Single CLI
 Support for vendor-specific technologies
SDN uses centralized controller to make
decisions and focuses on forwarding, not routing
Controller scalability, switch performance
Controller capabilities, interoperability
Questions in SDN Networks:

5. SDN Creates New Challenges for Operators
 For a Network Operator, SDN =
 New interactions
 New components that require redundancy
 New scalability and management issues
 How Does SDN Impact my Network?
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Overwhelmed Network Operator

6. New Data Centers: Great Environments for Deploying SDN
 Greenfield environment – all new equipment purchased at once
 Homogeneous network -- 100% SDN infrastructure
 Built from the ground-up, no risk of downtime during setup
 One administrative domain, little interaction with other networks
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7. What about existing ISP and Enterprise Networks?
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ISP Backbone Network

8. Existing Networks Built Piecemeal Over Multiple Years
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Provider Started at East Coast with One Equipment Vendor

9. Existing Networks Built Piecemeal Over Multiple Years
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Expanded to West Coast With Different Equipment Vendor

10. Multiple Technologies Support Large Networks
 Different Technologies Used Across Existing Network
 Different IGPs (OSPF, RIP), Route Reflectors for BGP scalability, Middleboxes
 Company acquisitions, sudden growth, vendor specific technologies → heterogeneity
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11. Large Networks Have Interactions with Other Networks
 Multiple Points of Presence for Interacting with Other Networks
 Interactions will continue to use BGP protocol for foreseeable future (even with SDN)
 These interactions are important → they define internal traffic patterns
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12. Other Existing Networks Have Similar Problems
 Other Networks May Not Be As Large, But Will Face Similar Problems
 ISPs, Enterprise Networks, Educational Networks, Service Providers
 Highly Diverse Network Ecosystem
 Lots of custom configurations, protocols, hidden interactions, outdated decisions
 Opposite of environment typically discussed when we talk about SDN
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13. Realities of Transitioning to SDN
 Takes time to migrate existing networks
 Some operators not ready to migrate portions of their network to SDN technologies
 BGP isn’t going away soon (still need to interconnect the Internet)
 Need Hybrid Network for Foreseeable Future
 Need to ensure different technologies in hybrid network play nice
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14. Network Operators….
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How Does an Operator Make Sure SDN Plays Nice In Their Existing Network?
What Tools Can These Use To Understand SDN’s Impact?

15. Mininet Enables Emulation of SDN Networks
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16. Mininet Lacks Support for Emulating Existing Networks…
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 Lacks Emulation Support for Key Components in Today’s Networks:
 Inter-domain routing (BGP between multiple AS)
 Intra-domain routing (Legacy IGPs, such as OSPF, RIP)
Cannot support
hybrid networks

17. Emulation Limited Regardless of Emulator
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 Cannot accurately emulate peer ISPs:
 Unpredictable routes, failures, policies, topologies, business & technical goals
 We need more than emulation...
Impossible to Emulate

18. MiniNExT
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Comprehensive Network Emulation of Intra-domain
combined with
Inter-domain Connectivity with Real Networks

19. MiniNExT’s Extends Mininet’s Emulation Support
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 Extends Mininet to Support BGP and IGP Protocols
 Now can support any network type, including hybrid networks
 Requires significantly less resources than emulation with virtual machines

20. [Real] [Emulated]
MiniNExT Goes Beyond Emulation with Real Connectivity
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 Combines Emulated Network with Real BGP Connectivity
 Multiplexes a real network’s existing BGP sessions
 Enables emulated and operational network to communicate with peers via BGP
BGP Sessions Multiplexed to
Provide Real Connectivity

21. MiniNExT Translates Network 1:1 into Sandbox Environment
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Real Network
MiniNExT
Sandbox
Both networks can
run at the same time
MiniNExT
Translation

22. Emulated with MiniNExT on a laptop
MiniNExT Combines Emulated Network with Real BGP
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Real BGP Sessions

23. MiniNExT Enables SDN Experiments
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Let’s Change The Data Center Network to SDN

24. MiniNExT Enables SDN Experiments
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New SDN Data Center (All Other Components The Same)

25. MiniNExT Emulated Networks Can Exchange Routes, Traffic
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26. MiniNExT Helps Operators Assess SDN’s Impact
Key Takeaways on MiniNExT:
 Enables 1:1 translation of any network into a sandbox environment
 Helps network operators take a holistic look at how SDN will impact their networks
 Makes it easier to define network transition plans with confidence
Additional Information on MiniNExT:
 Talk with me here at the conference
 Brandon Schlinker, bschlink@usc.edu
 GitHub Repository: MiniNExT
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