the remaining three countries constituting 1.85% of tests. It may be possible that if there were M-Lab servers in Turkey or Azerbajian, NDT tests would result in higher throughput measurements, however, we derive our conclusions from relative changes, rather than absolute numbers. Addditionally, users that are connected to anti-filtering tools during the test are likely to be recorded by M-Lab as originating from the country that the tool routes its traffic through, and therefore not included in our sample. We also constrain our expectations on the types of throttling or disruption that NDT will detect. As a diagnostic of direct connectivity between hosts, the test is based on traffic patterns that likely have yet to inspire scrutiny from intermediaries. Other protocols, such as those employed in VPN tunnels, HTTP proxies, Tor, voice-over-IP and streaming media, have at varying times been claimed to be subject to targeted interference, based on port or deep packet inspection. NDT’s measurement methodology is unlikely to detect more sophisticated discimination against specific forms or destination of traffic.

Lastly, we assume that intermediaries have not sought to interfere or game the data collection of M-Lab through artifically biasing measurements from hosts.

Findings {#sec:findings}
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Using median country-level 