Critical network management applications increasingly demand fine-grained flow level measurements. However, current flow monitoring solutions are inadequate for many of these applications. In this paper, we present the design, implementation, and evaluation of CSAMP, a system-wide approach for flow monitoring. The design of CSAMP derives from three key ideas: flow sampling as a router primitive instead of uniform packet sampling; hash-based packet selection to achieve coordination without explicit communication; and a framework for distributing responsibilities across routers to achieve network-wide monitoring goals while respecting router resource constraints. We show that CSAMP achieves much greater monitoring coverage, better use of router resources, and enhanced ability to satisfy network-wide flow monitoring goals compared to existing solutions.
Vyas Sekar, Michael K. Reiter, Walter Willinger, H