The architectural stability of the Internet was crucial in fostering the development of new applications and networking technologies by giving the former a stable base upon which to build and giving the latter a fixed set of requirements to support. However, in recent years this architectural stability has become a liability, as there are areas of increasing importance ? most notably inadequate support of security and availability, lack of adequate mechanisms for privacy, mobility, middleboxes, and data-oriented functionality ? where the original Internet architecture falls short. The persistence of the Internet's architectural deficiencies is not because they are intellectually intractable, but because they are beyond the reach of incrementally deployable changes. Based on this observation, the research team takes a different approach than recent clean-slate designs, focusing not on a new fixed architecture but instead on providing a platform to enable architectural innovation through incrementally deployable changes, without massive disruption in the infrastructure.
In this research project, the research team focuses on the ?hardware-defined functionality? challenge and proposes a ?platform for innovation? that allows the network infrastructure to support new architectures without changes to the underlying hardware. In particular, this approach will enable forwarding hardware to support a wide range of alternative designs. In addition, so that changes can be introduced alongside the current design, hardware will also be able to support multiple designs simultaneously.
The proposed platform will use a newly developed paradigm called Software-Defined Networks (SDN), currently embodied in the OpenFlow and NOX projects. OpenFlow is an open hardware forwarding interface. NOX is an open-source software platform that provides global abstractions to network management software and in turn communicates the decisions made by this software to the individual forwarding boxes. This effort will provide a solid foundation for more general SDN designs that are open, comprehensive and can meet long-term needs.
The research team will also explore and demonstrate applicability of the SDN approach including abstractions and programming model for different domains of network use. These include enterprise, WAN, home, and wireless. To demonstrate the ability of the proposed platform to support innovation in radically new network mechanisms, the research team will deploy prototype novel architectures on SDN.
If successful, the proposed approach would allow the use of known approaches and design proposals currently available in the literature to address many of the Internet's current problems, as these solutions would be incrementally deployable, without major disruption to the underlying infrastructure. Furthermore, current commercial efforts to address Internet?s deficiencies are disjointed, proprietary, and tailored for short-term needs. The next generation of SDN technology provides a solid basis for coordinated, long-term efforts to address critical needs in areas of security, mobility and support of content-centric application and services. More importantly, the proposed approach would allow the Internet to meet future requirements as they arise through incrementally deployable modifications, relieving network designers of the burden of predicting what these future requirements might be.
The "architecting for innovation" project focuses on enabling future computer networks to offer much richer services to improve network performance, reliability, security, and cost-effectiveness. The key idea is to capitalize on Software Defined Networking (SDN), a technology that allows a logically centralized controller to directly control how a distributed collection of switches handle network traffic. During the course of the project, we explored how SDN can transform different kinds of networks, from the data centers that host applications, through the backbone networks that deliver the data, to the cellular networks that connect to mobile users. For example, our research on SoftCell questioned the high cost and poor flexibility of modern cellular core networks (e.g., LTE). In SoftCell, we move functionality closer to the end users, through software switches (located at or near the cell towers), commodity hardware switches (with compact rule tables in the core of the network, and commodity servers (that offer services like parental controls and firewalls). SoftCell offers seamless mobility (so users' applications continue working across changes in location) and fine-grained policies (forhigher-level services like parental controls) through a novel addressing scheme and an algorithm for optimizing the use of limitedrule-table space in the switches. The research was in collaboration with Alcatel-Lucent, and we have had discussions with several carriers and cellular equipment manufacturers about our proposed techniques. As another example, our research on SDX (Software-Defined eXchange) is rethinking how service providers and content providers connect to each other, deep inside the Internet. Today, these networks meet at several hundred large Internet eXchange Points (IXPs) to exchange traffic and learn how to reach destinations throughout the Internet. However, today's IXPs are inflexible, offering only basic connectivity. In our SDX design, we support a much wider range of services, such as blocking unwanted traffic, specialized handling of content (like video), steering traffic through appliances (such as caches or transcoders that reduce the overhead for delivering the traffic), or balancing load across multiple copies of a Web site. We designed novel techniques that allow our SDX to scale to hundreds of participating networks delivering traffic for hundreds of thousands of blocks of destinations throughout the Internet. In addition, we designed a novel SDX application for server load balancing, and did a live demonstration of the service on an operational SDX in New Zealand. Together, these two projects demonstrate new ways the Internet can evolve to offer better service to end users, through cost-effectivecommodity equipment and flexible control software.
