White Paper Submission for the Workshop on Research Directions for the Next Generation Internet May 13-14, 1997, Vienna, VA by Robert J. Aiken with Tim Kuhfus, Richard Carlson, Network Research Manager, Linda Winkler of Argonne Argonne National Laboratory National Laboratory raiken@anl.gov 6519 Debold Rd. Sabillasville, Md. 21780 301-271-2919 301-271-2919 (fax) The research and education (R&E) community has a continuing need for persistent and scaleable network infrastructure supporting production and research applications as well as network research. This infrastructure is essential if researchers are to advance the state of the art in both advanced applications (for which reliable "production" network capabilities are required) and in the networking technologies that will provide the infrastructure of the future (for which "crashable research" network capabilities are required). Historically, the very different requirements of production and research have led to the use of distinct physical infrastructures for these two purposes. Yet, as the demand for increased bandwidth and capabilities continues to increase, the R&E community will have difficulty paying the high costs associated with acquiring and supporting parallel networks. Hence, we propose a new approach that will allow the use of the same physical infrastructure for both research and development purposes, and utilize real applications for "test driving" new technologies. This new approach is based on supporting various concurrent production layers as well as treating network infrastructure components as objects (e.g. switches, routers, muxs, circuits) that can be dynamically composed into virtual networks. This approach poses significant challenges that will require a major research effort to overcome (i.e., the NGI), but the potential benefits are great. These considerations lead us to conclude that the grand challenge in networking is to implement and concurrently support both advanced production network services, which applications can use with little risk, and persistent experimental network services, over as much of the same infrastructure as possible. This sharing of infrastructure can occur at numerous layers in the network, including the hardware, media, network bearer, transport, and application layers, and will occur with different network scopes, including the local (e.g., Campus), regional (e.g., MREN), and wide area (e.g., vBNS,ESnet, CAIRN). One goal of the NGI is to increase network bandwidth, but we must also become smarter and more efficient users of network technologies since the demand for network capabilities always exceeds available resources or the user's ability to pay for it. Adaptive temporal use and reuse of segmented object based network infrastructure is a basis for addressing these requirements. Quality of service (QoS) support can also aide by supporting concurrent virtual networks with radically different technical requirements (e.g., production and R&D networks) and dynamic policies. The benefits claimed for multi-modal network infrastructure in the R&E community also apply to telecommunication and Internet service providers, who also must support concurrent virtual infrastructures for both production and experimental purposes, as well as support multiple policy-based virtual networks on the same infrastructure. The benefits are especially applicable if these providers wish to make more efficient use of network resources in addition to being able to strain and test new network capabilities and features in experimental mode using real applications. A multi-mode adaptive infrastructure will greatly enhance the ability of these providers to tap underutilized bandwidth by allowing them to dedicate network resources on a finer granularity in both time and capability. A shared infrastructure will use the concept of a variable "bar" of production-level services to facilitate both the smooth introduction of new capabilities and the concurrent support of production and experimental activities. This concept supports on-demand experimental use and manipulation of network infrastructure, bandwidth, and quality of service, as well as a certain amount of concurrent elasticity where the production layer is perceived on a per application or virtual network basis. The bar is virtual in that it can be temporal (i.e., exist for short, medium, or long periods of time) or spatial (exist at various levels of network services at the same time), while concurrently providing for multiple levels of production and R&D-level services depending on the requirements and perspectives of the applications and the network R&D experiments. For example, we might see a production ATM service composed of a separate ATM switch and its bandwidth muxed out of the local loop. A researcher experiments with a network bearer service, such as IPv6, over the production ATM. The experimental ATM is supported on different switches and muxed bandwidth. Application scientists may view the IP layer and below as the production layer as they experiment with RSVP or reliable multicast for their message passing interface (MPI)-based application. Each of these scenarios has been provided separately in the past; i.e., a dedicated network for each scenario, with the possible exception of tunneling. The challenge is to provide concurrent support of these virtual networks on the same infrastructure. Each layer provides the opportunity and concurrent support for network research and production network services at the next layer up. Each production and research layer depends on the production bar of the services below it. The NGI must be application driven network research. Application developers are rarely eager to invest a large amount of effort and time to convert their codes to "test drive" new network technologies if the infrastructure is to be short lived. Yet the development and deployment of new architectures and protocols are extremely dependent on to test and stress the infrastructure or to validate that it works with real applications. For example, the I-WAY network developed to support Supercomputing 95 succeeded in demonstrating the benefits associated with an advanced pre-production infrastructure; yet this infrastructure evaporated immediately after the close of Supercomputing 95, making it difficult for many of the principal investigators to continue their collaborations. Network researchers need real applications and traffic to use and stress their experimental and production networks, and application developers are constantly seeking new network capabilities to enhance their computational environments. Neither group can progress without a persistent high-end, advanced infrastructure and without addressing the daunting cost associated with concurrently supporting both a production and experimental infrastructure. See http://www.anl.gov/ECT/Public/research/morphnet.html for a more thorough paper on multi-modal adaptive infrastructure. Robert J. Aiken (Bob), Argonne National Lab, Network Research Manager, raiken@anl.gov, 301-271-2919 "always keep your stick on the ice", (Red Green)