The Open Network Laboratory (ONL) is a remotely accessible network testbed designed to enable network researchers to conduct experiments using high performance routers and applications. ONL™s Remote Laboratory Interface (RLI) allows users to easily configure a network topology, initialize and modify the routers™ routing tables, packet classification tables and queuing parameters. It also enables users to add software plugins to the embedded processors available at each of the routers™ ports, enabling the introduction of new functionality. The routers provide a large number of built-in counters to track various aspects of system usage, and the RLI software makes these available through easy-to-use real-time charts. This allows researchers to expose what is happening fiunder the surfacefl enabling them to develop the insights needed to understand system behavior in complex situations and to deliver compelling demonstrations of their ideas in a realistic operating environment. This paper provides an overview of ONL, emphasizing how it can be used to carry out a wide range of networking experiments
