April 22, 2010 2 Comments
If you build it, will they come? In Field of Dreams, Ray Kinsella is confronted in his cornfield by a whisper that says, “If you build it, he will come,” which Ray believes refers to building a baseball field in the middle of a cornfield that will play host to Shoeless Joe and members of the 1919 Black Sox. Only Ray can see the players initially, leading others to tell him that he should simply rip out the baseball field and replant his corn crop. Eventually, other people see the players, too, and decide that keeping the baseball field might not be such a bad idea after all.
I can’t help but wonder if this scenario might have an analogy to the Global Environment for Network Innovations (GENI) effort, sponsored by the National Science Foundation. The GENI project seeks to build a worldwide network testbed to allow Internet researchers to design and test new network architectures and protocols. The project has many moving parts, and I won’t survey all of those here. A salient feature of GENI, though, is that it funds infrastructure prototyping and development, but does not directly fund research on that infrastructure. One of the most interesting challenges for me has been—and still is—how to couple projects that build infrastructure with projects that directly use that infrastructure to develop interesting new technologies and perform cutting-edge research.
Can prototyping spawn new research? This is, in its essence, the bet that I think GENI is placing: If we build a new experimental environment for networking innovation, the hope is that researchers will come use it. Can this work? I think the answer is probably “yes”, but it is too soon to know the answer to this question in this context. Instead, I would like to talk about how our GENI projects have spawned new research—and new educational material—here at Georgia Tech.
The Prototype: Connectivity for Virtual Networks. One of the the GENI-funded projects is called the “BGP Multiplexer” or, simply the “BGP Mux”. If that sounds obscure, then perhaps you can already begin to understand the challenges we face. Simply put, the BGP Mux is like a proxy for Internet connectivity for virtual networks (BGP is the protocol that connects Internet Service Providers to one another). The basic idea is that a developer or network researcher might build a virtual network (e.g., on the GENI testbed) and want to connect that network to the rest of the Internet, so that his or her experiment could attract real users. You can read more about it on the GENI project Web page.
Some people are probably familiar with the concept of virtualization, or creating “virtual” resources (memory, servers, hardware, etc.) based on some shared physical substrate. Virtual machines are now commonplace; virtual networks, however, are less so. We started building a Virtual Network Infrastructure (VINI) in 2006. The main motivation for VINI was to allow experimenters to build virtual networks on a shared physical testbed. One of the big challenges was connecting these virtual networks to the rest of the Internet. This is the problem that the BGP Mux solves.
Providing Internet connectivity to virtual networks is perhaps an interesting problem within the context of building a research testbed, but, in my view, it lacked broader research impact. Effectively, we were building a “hammer” that was useful for building a testbed, but I wanted to find a “nail” that was solving a real problem, could be published, and could also be used in the classroom. This was not easy.
Education: Transit Portal in the Classroom. I’ve been teaching a course called “Next-Generation Networking”, a course on Future Internet Architectures that I plan to discuss at more length on this blog at some point. Typical networking courses are not as “hands on” as I would prefer: I, for one, graduated from college without ever even seeing a router in person, let alone configuring one. I wanted networking students to have more “street cred”—they should be able to say, for example, that they’ve configured routers on a real, running network that’s connected to the Internet and routing real traffic. This sounds like lunacy. Who would think that students could play “network operator for a day”? It just sounds too dangerous to have students play around on live networks with real equipment. But with virtual networking and the BGP Mux, it’s possible. I recently assigned a project in this course that had students build virtual networks, connect them to the Internet, and control inbound and outbound traffic using real routing protocols. Seeing students configure networks and “speak BGP with the rest of the Internet” was one of my proudest days in the classroom. You can see the assignment and videos of these demos if you’d like to learn more.
Prototyping and research. Will the researchers come? Our own GENI prototyping efforts have been an exercise in “working backwards” from solution to networking research problem. I have found that exercise rewarding, if somewhat counter to my usual way of thinking about research (i.e., seek out the important problems first, then find the right hammer). I think now the larger community will face this challenge, on a much broader scale: Once we have GENI, what will we do with it? Some areas that seem promising include deployment of secure network protocols and services (our current protocols are known to be insecure), better support for mobility (the current Internet does not support mobility very well), new network configuration paradigms (networks of all kinds, from the transit backbone to the home, are much too hard to configure), and new ways of pricing and provisioning networks (today’s markets for Internet connectivity are far too rigid). We have just finished work on a large NSF proposal on Future Internet Architectures that I think will be able to make use of the infrastructure that we and others are building; in the coming months, I think we’ll have much more to say (and much more to see) on this topic.