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What exactly is skitter?

We at CAIDA have, unfortunately, overloaded the term skitter with three distinct meanings:

1. skitter is a measurement tool,
2. skitter is an infrastructure, and
3. skitter is a project.

The skitter project is more properly called the Macroscopic Topology Project. Archipelago (Ark) is the evolution of the skitter infrastructure, which consists of the skitter monitors, skitter measurement tool, several other tools, an internal web server for distributing destination lists, and a file storage server for collecting traces from monitors and providing the data for download via a public web server. The most significant improvements made so far have been the replacement of the communication component with a tuple space and the replacement of the skitter measurement tool with scamper.

The skitter measurement tool is a standalone program that reads a file of destinations and writes a file of traceroute paths. We are discontinuing our use of the skitter tool and switching to scamper. Scamper is an active measurement tool like skitter but more powerful and flexible, supporting IPv6 and ping measurements in addition to IPv4 and traceroute measurements. Scamper also supports TCP- and UDP-based traceroutes in addition to the ICMP-based traceroutes supported by skitter. Scamper has been in development for several years by our collaborator Matthew Luckie at the University of Waikato.

Scamper outputs traces in a different file format than skitter, but a tool is available that reads both skitter-format (arts++) and scamper-format (warts) files and outputs data in a textual format already familiar to researchers who analyze skitter files. In addition, a programming library is available for reading and writing the scamper format for researchers wishing to write their own analysis tools. For these reasons, we expect the switch to the new data format will have minimal impact on researchers. Source code to scamper and tools to analyze warts files are available at the scamper home page.