A CAIDA project to develop an operational prototype system that monitors the Internet, in near-realtime, to identify macroscopic Internet outages affecting the edge of the network, i.e., significantly impacting an AS or a large fraction of a country.

Interactive Interfaces

Overview Dashboard

High-level dashboard showing severity of country-, region-, and AS-level outages detected by IODA.

Alert Feed

Dashboard showing the raw outage alert feed generated by IODA.

Example Outages

Iraq (October 2016)

For the first week of October 2016, IODA detected nearly daily outages that significantly affected Iraqi Internet connectivity.

Gabon (September 2016)

In early September 2016, IODA detected daily outages in Gabon that significantly affected Internet connectivity. These outages were widely reported (e.g., by CNN, Cloudflare, Akamai, etc.) and were "initially imposed amid clashes between opposition protesters and security forces following the announcement that incumbent President Ali Bongo had won reelection by a slim margin".

Mexico (October 19 2016)

Starting around 7am (UTC) on October 19 2016, IODA detected an outage that affected Mexican Internet connectivity for just over an hour.


IODA combines information from three data sources, establishes the relevance of an event and generates alerts. The outage events and the corresponding signals obtained through automated analysis are displayed on dashboards and interactive graphs that allow the user to further inspect the data.

Global Internet routing (BGP)

We use data from ~500 monitors participating in the RouteViews and RIPE RIS projects to establish which network blocks are reachable based on the Internet control plane.

Internet Background Radiation

We process unsolicited traffic reaching the UCSD Network Telescope monitoring an unutilized /8 address block.

Active Probing

We continuously probe a large fraction of the (routable) IPv4 address space from CAIDA servers and use a methodology developed by University of Southern California to infer when a /24 block is affected by a network outage.

See the IODA project page for scientific references and for more information about our methodology.


This platform was supported by NSF grant CNS-1228994 [Detection and Analysis of Large-scale Internet Infrastructure Outages (IODA)].

This platform is also supported by Department of Homeland Security Science and Technology Directorate (DHS S&T) contract HHSP 233201600012C [Science of Internet Security: Technology and Experimental Research], and DHS S&T cooperative agreement FA8750-12-2-0326 [Supporting Research and Development of Security Technologies through Network and Security Data Collection].

Additional funding to work on visualization interfaces was generously provided by a Comcast research grant

This platform is also supported by the Open Technology Fund under contract number 1002-2018-027.

Additional funding to support this platform was generously provided by a grant from the Internet Society.

See the Acknowledgements page for more support information.