{"id":2296,"date":"2026-02-04T08:05:00","date_gmt":"2026-02-04T16:05:00","guid":{"rendered":"https:\/\/ant.isi.edu\/blog\/?p=2296"},"modified":"2026-02-27T09:53:43","modified_gmt":"2026-02-27T17:53:43","slug":"new-conference-paper-understanding-partial-reachability-in-the-internet-core-at-acm-nines-2026","status":"publish","type":"post","link":"https:\/\/ant.isi.edu\/blog\/?p=2296","title":{"rendered":"New conference paper: \u201cUnderstanding Partial Reachability in the Internet Core\u201d at NINeS 2026"},"content":{"rendered":"\n

Our new paper\u00a0\u201cUnderstanding Partial Reachability in the Internet Core\u201d<\/a>\u00a0will appear at the\u00a02026 New Ideas in Networked Systems (NINeS)<\/a>, a virtual meeting on February 10, 2026.<\/p>\n\n\n

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\"\"<\/a>
Durations of peninsulas (regions with partial Internet reachability) as seen in 2017q4, showing that most peninsulas are brief, but some persist for days or months (Figure 4 from [Baltra26a]). We see similar results in 2020.<\/figcaption><\/figure>\n<\/div>\n\n\n

From the abstract:<\/p>\n\n\n\n

\n

Routing strives to connect all the Internet, but compete: political pressure threatens routing fragmentation; architectural changes such as private clouds, carrier-grade NAT, and firewalls make connectivity conditional; and commercial disputes create partial reachability for days or years. This paper suggests persistent, partial reachability is fundamental to the Internet<\/em> and an underexplored problem. We first derive a conceptual definition of the Internet core<\/em> based on connectivity, not authority. We identify peninsulas<\/em>: persistent, partial connectivity; and islands<\/em>: when computers are partitioned from the Internet core. Second, we develop algorithms to observe each across the Internet, and apply them to two existing measurement systems: Trinocular, where 6 locations observe 5M networks frequently, and RIPE Atlas, where 13k locations scan the DNS roots frequently. Cross-validation shows our findings are stable over three years of data<\/em>, and consistent with as few as 3 geographically-distributed observers. We validate peninsulas and islands against CAIDA Ark, showing good recall (0.94) and bounding precision between 0.42 and 0.82. Finally, our work has broad practical impact: we show that peninsulas are more common than Internet outages<\/em>. Factoring out peninsulas and islands as noise can improve existing measurement systems<\/em>; their “noise” is 5x to 9.7x larger than the operational events in RIPE’s DNSmon. We show that most peninsula events are routing transients (45%), but most peninsula-time (90%) is due to a few (7%) long-lived events. Our work helps inform Internet policy and governance, with our neutral definition showing no single country or organization can unilaterally control the Internet core.<\/p>\n<\/blockquote>\n\n\n\n

A technical report with additional appendices is available from our website <\/a>and arXiv<\/a>.<\/p>\n\n\n\n

This paper is joint work of Guillermo Baltra, Tarak Saluja, Yuri Pradkin, and John Heidemann, building on work begun when Guillermo was a PhD student at USC and Tarak was a summer undergraduate researcher visiting USC from Swarthmore College.<\/p>\n\n\n\n

The work is supported by NSF via the EIEIO<\/a>, MINCEQ<\/a>, Internet Map<\/a>, and BRIPOD<\/a> projects, and by DARPA via AQUARIUS.<\/p>\n\n\n\n

Data created from the work is available at ANT<\/a>, and the input and validation data is available from ANT, RIPE Atlas, and CAIDA.<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

Our new paper\u00a0\u201cUnderstanding Partial Reachability in the Internet Core\u201d\u00a0will appear at the\u00a02026 New Ideas in Networked Systems (NINeS), a virtual meeting on February 10, 2026. From the abstract: Routing strives to connect all the Internet, but compete: political pressure threatens routing fragmentation; architectural changes such as private clouds, carrier-grade NAT, and firewalls make connectivity conditional; […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[419,418,24,317,417,58,355,250,420,329,44,5,416,390,57],"class_list":["post-2296","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-aquarius","tag-bripod","tag-conference","tag-eieio","tag-internet-map","tag-isi","tag-islands","tag-minceq","tag-nines","tag-outage","tag-outage-detection","tag-papers","tag-partial-reachability","tag-peninsulas","tag-usc"],"_links":{"self":[{"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2296","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2296"}],"version-history":[{"count":5,"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2296\/revisions"}],"predecessor-version":[{"id":2304,"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2296\/revisions\/2304"}],"wp:attachment":[{"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2296"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2296"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ant.isi.edu\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2296"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}