In China, multiple URLs show 100% failure rates across 3–7 ASNs with near-zero confirmed blockpage rates (e.g., hkleaks.ru, blockdx.co, libgen.space each at 100% failure, avg_confirmed ≈ 0), indicating that China increasingly uses non-blockpage mechanisms — connection drops, TCP anomalies — that evade blockpage-based detection while achieving complete access denial.

DNS censorship leaks geographically: Russia's neighbors show materially elevated censorship rates despite low independent censorship of their own — Lithuania 21.73%, Norway 12.04%, Finland 12.03% — compared to Russia itself at 43.59%, consistent with DNS queries from those countries transiting Russian infrastructure and being hit by Russian DNS injection.

§4.1, Table 1 evaluation

Russian transit censorship propagates to ASNs outside Russia: ASN 216071 (Netherlands) shows 38 top-10k URLs with 59% confirmed blockpage rate, ASN 6939 (Sweden) shows 4 URLs at 75%, and ASN 3214 (Germany) shows 4 URLs at 75%, all attributable to peering with Russian ASNs known to employ transit censorship.

§4.2, Table 2 evaluation

Venezuela and Cuba exhibit average unblocked rates of 68.83% and 69.70% respectively across 461,114 and 5,501 OONI tests, placing roughly 31% and 30% of probes as blocked — censorship rates comparable to documented heavy-censor states — despite being routinely excluded from standard censoring-country lists.

§4.3, Table 3 evaluation

Among the most commonly transit-censored popular URLs (top-10k rank, ≥90% confirmed blockpage rate from Russian transit ASNs, not blocked elsewhere in those countries), turbovpn.com appears alongside Russian opposition news and social-media pages, demonstrating that Russia's VPN-blocking lists propagate into foreign transit ASNs.

Table 5, §4.2 evaluation

Iran's censorship of refraction-networking proxies (Conjure via Psiphon) is not monolithic: different ISPs independently deploy different techniques and timelines. Over 800 million logged Conjure connections from July 2023–February 2025 across 10+ Iranian ASes show TCI (AS58224, ~33% of traffic) uses packet injection, while MCCI/Hamrah-e Avval (AS197207, ~22%) applies IP-based blocking, and some ASes (Parsonline AS16322, Shatel AS31549) show no proxy blocking at all.

2025-alaraj-iran-refraction §4 rst-injectionip-blockingpacket-injectiondpi

TTL-based path analysis showed that all censorship actions (DNS poisoning, HTTP injection, TLS resets) in the June 2025 shutdown occurred at the same network hop across all tested ISPs, indicating a single centralized national border gateway—likely TCI AS gateways—rather than per-ISP enforcement. Global BGP announcements were kept intact throughout, making the shutdown invisible to routing monitors while domestic connectivity collapsed.

2025-aryapour-stealth-blackout §4.5 dpidns-poisoningrst-injection

TLS connections to blocked services (instagram.com, telegram.org) were terminated by TCP RST immediately after the client's ClientHello, before any certificate exchange, confirming SNI-based DPI that reads the plaintext SNI extension and aborts the handshake. HTTP filtering additionally matched Host headers and URL keywords case-sensitively, with injected HTTP 403 pages or TCP RST responses, and case-change evasions were sometimes effective.

2025-aryapour-stealth-blackout §4.2, §4.3 sni-blockingdpirst-injectionkeyword-filtering

The August 20, 2025 unconditional RST event revealed an asymmetry in the GFW's triggering mechanism: for traffic originating inside China, both the client SYN and the server SYN+ACK each independently triggered three injected RST+ACK packets (six total per connection). For traffic to China from outside, only the Chinese server's SYN+ACK triggered RSTs — the foreign client's SYN alone was insufficient. This asymmetry implies the responsible device observed the SYN+ACK from the Chinese server as the trigger condition, not a port-match rule on the SYN.

2025-gfw-port443-rst §2.1, §2.2 rst-injectionport-blockingdpi

Iran's HTTP censor exhibits several parsing inconsistencies exploitable for evasion: (1) it is case-sensitive and ignores lowercase method variant "gET"; (2) it does not censor the Host header for HTTP version strings "HTTP", "1.1", and "example" (suggests a version regex of HTTP/.*); (3) when the Host header is absent, the path is not censored for versions "HTTP" and "HTTP/1"; (4) the body is never analyzed regardless of version. All HTTP and DNS censorship occurs at the same last-hop border node, suggesting centralized architecture.

2025-lange-i-ra-nconsistencies §3.2, Table 1 dpikeyword-filteringrst-injection

Russian TSPU devices directly block ECH by dropping ClientHello messages that contain both an ECH extension and the outer SNI hostname "cloudflare-ech.com" — the static outer SNI Cloudflare advertises in all its ECH configurations. Blocking affects both TLS and QUIC. ECH connections to servers with Cloudflare ECH support but outside Cloudflare's official IP ranges are NOT blocked. TCP segmentation alone or TLS record fragmentation alone did NOT bypass TSPU ECH blocking, but combining both techniques did circumvent it. TSPU has also added TCP reassembly capabilities that defeat previously effective fragmentation-only bypasses.

2025-niere-encrypted §5, Figure 5 dpirst-injectionmiddlebox-interference