TSG's SSL interception engine matches wildcard SNI patterns (e.g. "*tumblr.com") to decide whether to intercept (certificate-replace) a connection, but a separately-maintained "SSL Decryption Exclusions" allowlist takes priority over interception policy -- a domain on that list is never intercepted even if it matches an active policy.

TSG automatically generates recurring weekly "SNI Report of Overseas APP" and companion "Server IP and Location of Overseas APP" reports at what is almost certainly a China-national (not export-customer) scale — single weekly runs process from ~5.7 trillion to over 135 billion rows and up to ~775TB/week — breaking down QUIC.SNI/SSL.SNI/HTTP.Host traffic per named blocked-in-China platform (YouTube, Facebook, Google, Twitter, Instagram, Telegram, WhatsApp, Netflix, BBC, Viber, Line, Snapchat, Gmail, HBO, and more), down to individual CDN edge hostnames (e.g. specific scontent-*.fbcdn.net and rr*---sn-*.googlevideo.com nodes ranked by bytes). The report series recurs weekly from at least Feb 2023 through Mar 2024.

A dedicated internal "运营商前端分析团队" (Carrier Front-end Analysis Team) produces weekly, carrier-specific traffic-analysis reports explicitly titled "新疆移动流量分析报告" (Xinjiang Mobile Traffic Analysis Report) and "新疆联通流量分析报告" (Xinjiang Unicom Traffic Analysis Report), with instances dated from at least July 2022 through March 2024. One instance (Xinjiang Mobile, 2023-05-15) reports total carrier bandwidth of 4.4Tbps (1Tbps access bandwidth), 27.34PB of weekly throughput, 123 distinct identified application-layer protocols, and a section (4.1, pages 17+) explicitly tracking server IP/location for 28 named overseas apps (BBC, Discord, ESPN, Facebook, Gmail, Google, Hulu, Instagram, Netflix, Reddit, Skype, Telegram, Twitter, Uber, WhatsApp, Wikipedia, YouTube, Zoom, etc.).

Recurring automated "Tiangou Secure Gateway — SNI Report of Overseas APP" documents (weekly, multiple recurrences across 2023-2024) enumerate every distinct QUIC.SNI/SSL.SNI/HTTP.Host value observed per major foreign platform (Netflix, WhatsApp, Telegram, Twitter, YouTube, Signal- adjacent services, etc.) with packet/byte counts, processing runs at up to ~6.3 trillion rows per report. QUIC SNI is tracked as a distinct column from TLS SNI, showing the pipeline separately fingerprints HTTP/3 traffic.

A recurring weekly 'Tiangou Secure Gateway / Server IP and Location of Overseas APP' report series tracks per-app server-IP geolocation for Instagram, Snapchat, Telegram, and Likee traffic, with entries repeatedly geolocated to Almaty, Pavlodar, and Nur-Sultan, Kazakhstan across late 2023-early 2024 -- consistent with (though not conclusive proof of on its own, given ambiguity over whether the geolocated IPs are CDN edge nodes or another artifact) an operating Kazakhstan TSG deployment continuously monitoring named social/messaging platforms.

The tango/kni (Kernel Network Interface) repo shows TSG's SNI/TLS-ClientHello-based interception logic (kni_entry.cpp) receiving dedicated 2024 fixes for handling TLS ClientHello fragmented across multiple packets ("ssl chello frag") and a "chello first packet hit intercept policy" bug, on top of a long-standing (2020) "dynamic bypass" feature that replaced raw-ClientHello matching with JA3 TLS fingerprints, plus counters for SSL certificate-pinning detection.

TSG's SSL parsing plugin (MESA_Platform/ssl) explicitly detects and 'detains' TCP-fragmented TLS ClientHello packets, buffering/reassembling them before running SNI/certificate inspection (tickets TSG-16297, TSG-19861), with dedicated per-session detain-timeout metrics added in 2024 -- meaning ClientHello fragmentation is a defeated, not just untested, SNI-blocking evasion technique against this DPI engine.