Internal Jira tickets reveal that Psiphon lacked obvious protocol signatures, forcing censors to fall back to IP-based blocking of Psiphon3 client IPs combined with a 'whitelist protection mechanism' that allows traffic when the destination SNI matches a popular domain—an explicit collateral-damage tradeoff documented in the Confluence file 'GTN498 The collateral damage analysis of Psiphon3 Blocking.' A ticket from the Ethiopia (E21) deployment shows customers complaining that the VPN deny policy inadvertently blocked non-VPN applications.

TSG's Context-Based Detector (CBD) evaluates circumvention tool signatures across JA3/JA4 TLS fingerprints, SSL certificate issuer fields, UDP payload length, first-packet byte patterns, server IP ranges, and FQDN matches, often combining multiple conditions with logical AND. Of 29 VPN and circumvention tool signatures logged in the VPN Signature File Update Log (March–November 2024), 21 carry risk level 5 (the maximum), indicating aggressive prioritization of blocking major tools including ExpressVPN, NordVPN, Tor Browser, and Psiphon.

§4.1, §4.1.2, Table 3, Table 4 detection

Measurements of TCP RST injectors confirm that GFW II and GFW III consistently yield a seed key k=13, matching TSG's default seed_key parameter in trick_algo_getrandval_with_seed. The probability of sharing TSG's default value of 13 by chance is approximately 10⁻⁴⁴, strongly indicating these GFW components run Geedge Networks TSG code or a close derivative.

§6.3, Table 7 deployment

TLS ClientHello length-field permutation tests show that GFW II's parsing behavior matches an older tagged version of TSG's SSL module, while Kazakhstan and Pakistan (DROP mode) exhibit parsing behaviors consistent with TSG QUIC plugin deployments. QUIC version fingerprinting further confirms Kazakhstan runs an older version of TSG's QUIC parsing code, and Myanmar's supported QUIC versions exactly match TSG's, spanning at least five countries confirmed or plausibly running TSG components.

§6.4, §6.5, Table 8, Table 9 deployment

TSG's DNS parser enforces a hard limit of exactly 17 compression-pointer jumps per query; a query with 18 jumps causes domain name extraction to fail and suppresses the injection response. Only China's GFW Injector 2 shares the full combination of DNS flags 0x8180, compression-pointer encoding in injected answers, and the 17-pointer capability boundary, confirming it runs TSG's DNS injection code.

§6.1, Table 5 deployment

Across three testers all on MTS, whitelist behavior varied by network segment in ways that could not be explained by protocol configuration alone; the operator has zero confirmed data for MegaFon, Beeline, or T2 under whitelist conditions. The open question of whether whitelist policy (site+IP list) is centrally issued by the Ministry of Digital Development while implementation differs per carrier remains unresolved, making cross-carrier generalization of any circumvention finding unreliable.

2026-amigocarra-bypassing-russian-federation-s Issue body — questions 1 and 2 ip-blockingsni-blocking

During apparent whitelist-activation periods on MTS mobile LTE, the affected user experienced a complete network blackout in which even explicitly whitelisted resources (gosuslugi.ru) were inaccessible — behavior inconsistent with a standard default-deny CIDR+SNI whitelist, which should pass approved destinations unconditionally. The operator concludes this may represent a stricter enforcement variant, a SIM-specific restriction, or a mechanism entirely separate from the documented whitelist architecture.

2026-amigocarra-bypassing-russian-federation-s Issue body — main mystery paragraph ip-blockingsni-blocking

VLESS+Reality with uTLS and decoy SNI pointed at popular domains (vk.com, cloudflare.com) bypasses standard DPI blocking on MTS and has operated stably for one real user over several weeks with thousands of connections logged. However, an identical configuration failed to establish a single connection for a second user on the same carrier but in a different network segment (Moscow number vs. regional/southern number), including during periods confirmed to be outside whitelist activation.

2026-amigocarra-bypassing-russian-federation-s Issue body — confirmed working / not working sections dpisni-blockingip-blocking

Article 19 documents that Iran's National Information Network (NIN / SHOMA) was designed with explicit reference to China's Great Firewall as a model, with institutional mirroring: Iran's Supreme Council of Cyberspace parallels China's Cyberspace Administration of China, and both governments share a "cyber sovereignty" doctrine used to justify domestic content controls and cross-border technology transfer. The report frames Iran's filtering infrastructure as deliberately architected to replicate GFW capabilities, not as an independently developed system.

2026-article19-tightening-the-net §2, §3 dpisni-blockingdns-poisoningip-blockingbgp-hijackthrottling

CensorLess vanilla mode costs $0.27/month for a single proxy processing 6.76 GB of traffic monthly, a 97.1% reduction (34.4×) over SpotProxy's optimal single-NIC configuration ($9.28/month). The private mode, which adds a t4g.micro EC2 VPS for end-to-end encryption via SOCKS, costs $3.41/month — still 63.3% cheaper than SpotProxy's cheapest option. Costs remain below $3.50/day even when scaling to 300 proxies.

2026-kang-censorless-serverless §6.3, Figure 6 ip-blockingsni-blockingdns-poisoning

DPYProxy-DNS's automated probe-and-select mode identified a working DNS circumvention in an average of 13.78 seconds (median 12.90s) in China and 12.32 seconds (median 8.28s) in Iran across 100 runs each; best-case startup was 0.32s (China) and 0.47s (Iran) when the first-tried combination succeeded, while worst-case exceeded 30.72s in China and 58.16s in Iran due to the slow Last Response mode (3s fixed wait per attempt) being selected early in the randomized probe order.

2026-lange-towards §6.3 dns-poisoningsni-blockingip-blocking