The Challenge of Partial Reachability in Active Measurement

Heidemann, John
USC/Information Sciences Institute

citation

John Heidemann 2026. The Challenge of Partial Reachability in Active Measurement. Invited talk at CAIDA AIMS-19 Workshop. [PDF]

abstract

A number of systems study Internet outages, looking to detect when people drop off the network. We suggest that partial reachability is a problem affecting even more people than outages–when Internet users in some locations cannot reach other parts of the Internet because of persistent network unreachability. We infer partial reachability by reanalyzing data from Trinocular outage detection and RIPE Atlas. We show that partial reachability is at least as common as outages in Trinocular, that it accounts for more than half of the problems seen in RIPE’s DNSmon, and we suggest that it is at root of corner cases in other Internet-wide measurement platforms.

reference

@misc{Heidemann26a,
  author = {Heidemann, John},
  title = {The Challenge of Partial Reachability in Active Measurement},
  howpublished = {Invited talk at CAIDA AIMS-19 Workshop},
  month = feb,
  year = {2026},
  sortdate = {2026-02-24},
  project = {ant, minceq, eieio, minceq, bripod, aquarius},
  jsubject = {topology_modeling},
  jlocation = {johnh: pafile},
  keywords = {partial reachability, internet outage,	internet definition},
  url = {https://ant.isi.edu/%7ejohnh/PAPERS/Heidemann26a.html},
  pdfurl = {https://ant.isi.edu/%7ejohnh/PAPERS/Heidemann26a.pdf},
  myorganization = {USC/Information Sciences Institute},
  copyrightholder = {authors}
}