CAIDA : tools : measurement : skitter

skitter

skitter is a tool for actively probing the Internet in order to analyze topology and performance.

On Feb 8, 2008, after 10 years of data collection and 4TB of data, we deactivated skitter data collection and transitioned to our next generation topology measurement infrastructure named Archipelago (Ark). We already perform large-scale topology measurements on Ark, and we recommend researchers use this new dataset, which employs an improved measurement methodology. The new IPv4 Routed /24 Topology Dataset collected on Ark extends back to Sep 13, 2007 and overlaps with the last five months of skitter data.

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skitter Goals

Sample Visualization from skitter Data

The research goals of this project are described on our Macroscopic Topology Measurements page. Specific data collection goals include:

Measure Forward IP Paths
skitter records each hop from a source to many destinations. by incrementing the "time to live" (TTL) of each IP packet header and recording replies from each router (or hop) leading to the destination host.
Measure Round Trip Time
skitter collects round trip time (RTT) along with path (hop) data. skitter uses ICMP echo requests as probes to a list of IP destinations.
Track Persistent Routing Changes
skitter data can provide indications of low-frequency persistent routing changes. Correlations between RTT and time of day may reveal a change in either forward or reverse path routing.
Visualize Network Connectivity
By probing the paths to many destination IP addresses spread throughout the IPv4 address space, skitter data can be used to visualize the directed graph from a source to much of the Internet.

Research and Publications Based on Skitter Data

CAIDA publications based on skitter data
Non-CAIDA publications based on skitter data (list compiled based on Internet search)
Non-CAIDA publications using skitter data (list compiled based on feedback from skitter data users)
Non-CAIDA publications referencing skitter tool or data
Skitter data application procedure and official CAIDA Skitter Data Request form for academic researchers and corporate entities (including corporate researchers) who participate in CAIDA's membership program who wish to download/use skitter data

About skitter Measurement Traffic:

If you are receiving 52-byte ICMP echo request packets from an IP address belonging to one of our current monitors, they are from skitter (assuming they're not from someone spoofing the source address). We would like sites to be receptive to skitter measurements at low frequency. CAIDA's measurement efforts are intended to help users, providers and researchers understand the complexities in the current and future Internet. skitter research will provide the community with insight into the complexity of a large, heterogeneous, and dynamic worldwide topology.

If you are receiving skitter measurement traffic and would like measurements to be discontinued to your site, please send mail to skitter-configs@caida.org. We will discontinue the measurements to your site. We would appreciate a reason for the request, but it's certainly not necessary. However, please include the IP addresses of the hosts that you wish to have removed from the skitter database. Note that if your site is not measured, it will not show up in any of the pictures we provide nor any of the routing change measurements and plots.

Status of skitter monitors
Recommended specifications for new skitter monitors

Please send any questions regarding skitter to skitter-info@caida.org.