Towards Testbed-Wide Traffic Profiling for FABRIC

Network testbeds are important tools in modern research, and they require substantial observability by users and operators. Observability of a testbed helps to capture transient conditions of the testbed that might be difficult to reproduce, and that affect the testbed's performance or the outcomes of user experiments. Having a programmable network profiler helps provide this observability for the testbed's dataplane by summarizing the network activity on the testbed. But building a testbed-wide profiler is non-trivial since it involves making various kinds of technical trade-offs. This paper introduces Patchwork: a programmable network profiler for the FABRIC testbed. Patchwork programmatically samples the dataplane to create a trace of its contents over time. Unlike features like NetFlow or sFlow, Patchwork places minimal burden on operators to provide a configurable interface for flexible traffic sampling to the testbed's users. Using Patchwork, we present the first ever profile of FABRIC's network traffic among its sites in two continents. We discuss both testbed-wide and site-specific traffic characteristics. We also describe ongoing work to enrich and extend this profile to obtain a deeper understanding of FABRIC's traffic profile, and enable researchers to form more detailed insights when using FABRIC.