A design doc for a DNS/proxy gateway hosted at a public IIE-branded DoH endpoint (iie-public-doh.com) force-resolves the domains of ~40 target websites to a non-transparent SNI-routing proxy (which reads the ClientHello SNI without decrypting) while all other domains resolve normally; an 'open target resource discovery' module actively crawls each target site with a headless Chrome driver to map its dependent resource domains and assess their domestic-vs-overseas availability, feeding the allow-list.

An internal measurement-study report documents researchers live-testing the public DPYProxy TLS/SNI record-fragmentation tool against the GFW from inside China, against a control run from a German VPS. On a GFW IP-blocklisted Wikipedia IP, SNI fragmentation of any tested size (1/5/10/20 bytes) still ended in a server-side RST (though 1-5 byte fragments reached ServerHello before RST vs. 10-20 byte fragments RSTing right after ClientHello); on a non-blocklisted IP for the same domain, SNI fragmentation fully bypassed SNI-based blocking and returned a normal HTTP 200 response, matching the Germany baseline. The same report notes that testing Psiphon triggered roughly 5-10 minutes of residual censorship that also blocked other, unrelated circumvention tools from the same vantage point.

A MESA-affiliated researcher's experiment log documents live testing of Psiphon and a TLS-fragmentation SNI-evasion tool (DPYProxy) against the real Great Firewall from inside mainland China. Fragmenting the TLS ClientHello/TCP stream into very small (1-5 byte) segments bypassed GFW SNI-based blocking of a non-blocklisted Wikipedia IP, while larger fragments (10-20 bytes) did not; a separately IP-blocklisted Wikipedia IP still failed regardless of fragmentation. Testing Psiphon also appeared to trigger a ~5-10 minute window in which the researcher's own unrelated circumvention tool stopped working.

Geedge's TSG self-check test suite (run against firewall version v23.07.18-591aed7) enumerates the product's full interference capability set: SSL bypass/intercept (including handling of expired, self-signed, and untrusted-root certificates), HTTP/SSL proxy actions (redirect, block, replace, hijack, insert), three distinct firewall deny modes (silent drop, TCP RST, blockpage), and DNS deny modes (silent drop, A-record redirect, AAAA-record redirect, including TTL-range variants).

As of TSG v23.07, FQDN matching supports left-anchored prefix/wildcard matching (e.g. 'voice-group-80x-api.*'), added specifically so a Fujian domestic deployment could detect domains with a fixed subdomain prefix but rotating remainder. Earlier versions only supported exact FQDN match.

For Hotspot Shield's IKEv2 mode, SNI-only blocking failed because logged SNI hits corresponded to the VPN's own domain/CDN traffic while tunnel-negotiation domains (journalissue.us, middle-island.us) went unlogged; switching the rule to match DNS query name (qname) for those specific domains successfully blocked the connection.

Geedge fingerprinted several V2Ray-based VPN apps by their fixed API/bootstrap domains rather than protocol characteristics — blocking "V2 Pro" via pro.mucacherry.org, "V2 VPN" via v2.mucacherry.org, and "V2Net VPN" via api.v2net.live plus 5 rotating free-node domains (free1-5.v2n3t2.online / v2n3t.online) the app uses to fetch node lists.