Four myths about GENI (and one recommendation) Constantine Dovrolis College of Computing Georgia Tech

The summary of my position  The main motivations behind GENI and FIND are questionable  Myth-1: The “lack of adoption” argument  Myth-2: “An experimental facility such as GENI will lead to better networking research (or higher deploy-ability)”  Myth-3: “The Internet architecture is ossified”  Myth-4: “Clean-slate architectural research will lead to a better future Internet than the evolution of the current architecture”  A recommendation to NSF and the research community:  Do not put all your eggs in one basket  Embrace and support evolutionary Internet research  Provide experimental facilities that evolutionary research desperately needs

Myth-1: If the real-world does not adopt our architectures/protocols, then something is wrong with the real-world..  Or is it that something is wrong with our architectures and protocols?  What happened to IPv6, IntServ, IP Multicast, and so many other architectural proposals?  GENI proponents say that the real-world (mostly ISPs and router vendors) does not have the incentive to deploy innovations at the network layer  In reality though, ISPs never stopped deploying new protocols/technologies when they actually need them  Think of MPLS, BGP route reflectors, traffic classifiers/differentiators at forwarding plane, NIDS, etc  The real-world adopts “evolutionary mutations” that address a real need and provide an advantage/gain to the deployer  Think in biological terms: mutations, natural selection, survival of the fittest

Myth-2: Prototype implementations and testbed experiments will lead to increased deploy-ability  Most previously proposed “failed architectures” were actually implemented and run on various testbeds  Remember MBone? 6-Bone? RSVP+IntServ implementations?  Testbeds and prototypes do not prove “deployability”  All recent congestion control proposals (e.g., XCP) have been implemented and run on testbeds  The main issue with any testbed/experimental facility is that it does not carry real user traffic  Real users will not use a buggy/experimental network  Plus, a testbed cannot capture the complex economic/incentive issues that were the key factor behind the failure of many previous architectures  Routing research without considering policies and incentives?  On the other hand, the real-world has repeatedly deployed new protocols/technologies that lacked testbed experiments, but that evolved while running in production networks  Think of the long TCP evolutionary path

Myth-3: The Internet architecture is ossified  What can we learn from biology and complex systems?  In any complex system, the core components (evolutionary kernels) need to be conserved, so that complexity and diversity can emerge at the periphery of the system  Think of Doyle’s bow-tie architecture, or the TCP/IP waist of the protocol hourglass  The network layer represents an evolutionary kernel. It needs to be conserved (few and minor changes) so that innovation and diversification can continue at the transport/application layers and at the physical/link layers  My (serious) prediction: The Internet of 2020 will be running a backwards-compatible, evolved version of IPv4  The research community needs to understand the “conservation of evolutionary kernels” principle, and focus its innovative energy on higher and lower layers  Where innovation thrives

Myth-4: A clean-slate architecture will lead to a better future Internet than the evolution of the current architecture  A clean-slate architecture in 2007, based on the current economic/technological constraints, objectives, and requirements will probably be irrelevant in 5-10 years from now  The environment in which a network architecture “lives” is changing faster than the timescales of academic research  How long does it take to think, design, prototype, experiment, publish and fund a complete clean-slate architecture? 5-10 years?  Clean-slate architectural research would have a chance if we knew the actual objectives and constraints in 5-10 years from now  But we don’t have this luxury  On the other hand, evolutionary research does not need crystal ball  Focus on current objectives, constraints and problems  Provide evolutionary solutions that do not break existing net  Repeat as needed

A recommendation to NSF & the community  Embrace and support evolutionary research  Evolutionary research does not mean “incremental patches” or ad-hoc/easy research  An unfortunate misconception that has gone unnoticed  Evolutionary research has a high impact on the Internet and to the broader society  Evolutionary research does not benefit from testbeds and toy-prototypes  Instead, it needs Internet-based facilities such as:  Distributed Internet monitoring & probing infrastructures  Experimental ISPs with connections to real ISPs  Experimental but production-level services (e.g., an NSF- funded YouTube-like service) that can attract real users to instrumented facilities

If you are interested to read more..  Paper under submission: “What would Darwin think about GENI and FIND? Evolutionary versus clean-slate Internet research”  me for a copy