The survey identifies 'soft censorship' — including throttling, packet-loss injection, and quality-of-experience degradation — as detected by only 2 of 13 surveyed platforms (rTurtle and UBICA) as of 2015. The paper explicitly flags this as a measurement gap, noting that soft censorship symptoms are indistinguishable from ordinary network congestion without ground-truth probes placed outside the censor's network.
From 2015-aceto-internet — Internet Censorship detection: A survey
· §3 / Table 2
· 2015
· Computer Networks
Implications
Circumvention tools should include baseline bandwidth benchmarks using uncensored control paths so that throttling can be distinguished from ordinary ISP congestion and accurately surfaced to users.
Design protocols to degrade gracefully under sustained throttling (e.g., switching to lower-bandwidth modes or alternative routes) rather than treating only hard blocks as an adversarial signal requiring response.