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GENI: Global Environment for Network Innovations

Jennifer Rexford

On behalf of Allison Mankin (NSF)

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Is the Internet broken?

• It is great at what it does. –Everyone should be proud of this. –All sorts of things can be built on top of it.

• But…–Security is weak and not getting better.–Availability continues to be a challenge.–It is hard to manage and getting harder. –It does not handle mobility well.–A long list, once you start…

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FIND: Future Internet Design

• NSF research initiative– Requirements for global network of 10-15 years out?– Re-conceive the network, if we could design from scratch?

• Conceive the future, by letting go of the present:– This is not change for the sake of change– Rather, it is a chance to free our minds– Figuring out where to go, and then how to get there

• Perhaps a header format is not the defining piece of a new architecture– Definition and placement of functionality– Not just data plane, but also control and management– And division between end hosts and the network

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The Importance of Building

• Systems-oriented computer science research needs to build and try out its ideas to be effective– Paper designs are just idle speculation– Simulation is only occasionally a substitute

• We need:– Real implementation– Real experience– Real network conditions– Real users– To live in the future

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GENI

• Experimental facility– MREFC proposal to build a large-scale facility– Jointly from NSF’s CS directorate, & research community– We are currently at the “Conceptual Design” stage– Will eventually require Congressional approval

• Global Environment for Network Innovations– Prototyping new architectures– Realistic evaluation– Controlled evaluation– Shared facility– Connecting to real users– Enabling new services

See http://www.geni.net

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Three Key Ideas in GENI

• Virtualization– Multiple architectures on a shared facility– Amortizes the cost of building the facility– Enables long-running experiments and services

• Programmable– Enable prototyping and evaluation of new architectures– Enable a revisiting of today’s “layers”

• Opt-in on a per-user / per-application basis– Attract real users

• Demand drives deployment / adoption– Connect to the Internet

• To reach users, and to connect to existing services

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Slices

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Slices

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User Opt-in

Client

Server

Proxy

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Realizing the Ideas

• Slices embedded in a substrate of resources– Physical network substrate

• Expandable collection of building block components• Nodes / links / subnets

– Software management framework• Knits building blocks together into a coherent facility• Embeds slices in the physical substrate

• Builds on ideas in past systems– PlanetLab, Emulab, ORBIT, X-Bone, …

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Challenges in Realizing the Goals of GENI

Jennifer RexfordPrinceton University

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What is the Goal of GENI?

• Network architecture research–Revisit the definition and placement of function–For better security, scalability, manageability, …

• Enable evaluation of network architectures–In a controlled and realistic fashion–With long-running deployment studies–With real user traffic, and real network conditions

• Challenges–Using GENI effectively–Designing, building, and running GENI

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Challenge #1: Theory and Systems

• “Clean-slate” network architecture research– Creative ideas unconstrained by existing artifacts– A chance for theory to drive future architectures– … and to finally have a “science of design” for networks

• Emphasis on deployment and experimentation– Evaluation of prototypes under realistic conditions– A chance for systems work to drive future architectures– … and to finally have a “tech transfer” path

• Can we connect good theory with good systems?– Turning distributed algorithms into network protocols

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Challenge #2: Revisiting the Layers

• Today’s architecture is a collection of layers– Application, transport, network, link, …– Organizing principle for networking textbooks– Fragmentation of the research community

• Revisiting the division of functionality is hard– Inherently a “cross-layer” research problem– Benefits from expertise across multiple layers

• Can we, as researchers, cross the layer boundaries?– And create tools for decomposing a system, and

analyzing the resulting complexity?

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Example Research Questions

• Traffic management– Today: congestion control (end hosts), routing protocols

(routers), and traffic engineering (network operators)– Tomorrow: discovering the right division of labor

• Scalable routing– Today: exciting theoretical results in compact routing– Tomorrow: turning those into network protocols

• Mobile hosts– Today: network backbone ignores host mobility– Tomorrow: wired-network support for mobile hosts

• Adversarial settings– Today: protocols based on trust in the participants– Tomorrow: protocols that are robust to greed and malice

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These are Hard Problems

• Interdisciplinary research is hard– Theory and systems– Crossing, and revisiting, the layers

• But these issues are at the core of networking– We must grapple with them– Not just to “fix the Internet”, but also as scholars

• To move networking from a problem domain to an intellectual discipline

• To teach our students better

• GENI is an enabler, but not a solution

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Building Networks like GENI

• Programmable virtual networks– A distributed, programmable experimental facility– Shared on a small timescale, carrying real user traffic

• Theoretical challenges– Embedding a virtual topology in a shared substrate– Coordinating resource allocation across a federation

• Platform for investigating the challenges– VINI: VIrtual Network Infrastructure– http://www.cs.princeton.edu/~jrex/virtual.html

• Maybe net virtualization is itself an architecture– No “One Architecture to Rule Them All”…