geedge.lantern.io
detection confidence: medium public

TSG's FQDN-based blocklist matching handles Internationalized Domain Names (Punycode/'xn--' prefixed non-ASCII domains), including automatic transcoding between Unicode and Punycode forms during policy sync between deployment sites -- confirmed via a bug where inconsistent validation of Unicode-vs-Punycode-entered domains broke policy sync between two Fujian sites.

CM更新至24.07后,CM自动将 *xn--xxxx.com 转义为中文域名...部分诈骗网站是 中文.net 这种格式

Defense implications

censorscn
techniquesdpi
productstsg
capabilitydpi-signature

extracted_by: claude-sonnet-5 · added 2026-08-26 · id: 2026-idn-punycode-fqdn-matching

Related findings

deployment

An internal TSG operations/troubleshooting manual lays out TSG's full traffic pipeline (NIC -> mrzcpd/marsio capture driver -> sapp DPI engine -> firewall/proxy(KNI->TFE)/active-defense/WAN-NAT policy branches) and shows engineers using maat_redis_tool to pull the live Redis-synced blocking policy tables (TSG_SECURITY_COMPILE, TSG_OBJ_IP_ADDR, TSG_OBJ_APP_ID) and filter them by numeric policy/object ID to debug why a block rule isn't firing.

detection

The internal 'MAAT网络流处理配置统一描述框架' engineering manual (v3.1.20, author 郑超, 2021) documents MAAT's Redis-synced rule-compilation framework and its RuleScan/Hyperscan-based pattern-matching engine (libmaatframe.so / librulescan), and records that RuleScan's fast-scan feature caused a production outage on 2019-03-19 and has been disabled ever since.

deployment

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.).

detection

TSG's app-traffic classification relies on an updatable "App Sketch DB" component (uploaded as a versioned file to each deployment). A version bump at the Xinjiang Unicom province-exit + IDC site increased identified application-traffic share from 23% to 68% of total traffic within days, with ByteDance-attributed traffic alone rising from ~100TB/day to ~500TB/day identified, illustrating both the scale of traffic under classification and that classification itself is a frequently-updated, centrally-distributed database rather than a static build-time artifact.

deployment

A weekly "新疆移动流量分析报告" (Xinjiang Mobile Traffic Analysis Report), authored by the "运营商前端分析团队" (Carrier Front-End Analysis Team), directly ties the SNI/Server-IP overseas- APP report format to the China Mobile Xinjiang branch specifically, and states the pipeline identifies 126 distinct application-layer protocols including multi-layer tunnel nesting such as STUN.DTLS and STUN.RTP.RTCP.DTLS — i.e. it decomposes and classifies nested WebRTC-style transport stacks, not just top-level TLS/QUIC.

deployment

Side-by-side internal performance comparison across Xinjiang (China Mobile carrier deployment, hostname cmcc-xj-server1-sapp-244), Fujian (domestic), and Ethiopia (E21) explicitly references the same 'app_sketch_maat' diagnostic log format at all three sites, confirming the identical AppSketch app-fingerprinting stack is used for domestic Xinjiang surveillance and for the exported Ethiopia deployment.