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.

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.

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.

TSG's DPI signature engine is organized around named internal components confirmed by config paths and error logs: SAPP (installed at /home/mesasoft/sapp_run or /opt/tsg/sapp), MAAT (config at .../tsgconf/maat.conf, tied to a Redis-backed APP_SIG_SESSION_ATTRIBUTE_STRING table), and App-SketchDB (a versioned, centrally-maintained app-identification signature database pulled periodically by field deployments). One deployment's provincial gateway alone had 1,667 TCP/UDP first-packet payload signature entries active (396 at the IDC site), confirming payload-prefix matching as a live, large-scale detection method, including custom byte-prefix entries for DingTalk and WeChat.

Real TSG session logs from device "XXG-TSG-BJ" (Beijing) show live production blocking of named commercial VPN apps by app-signature: 206 of 213 sampled sessions carry security_action "deny_quarkVPN01" against app field "quarkVPN0622.quarkVPN0619" (destination IPs in Germany, Russia, US, Australia, Bangladesh); a second log from the same device shows security_action "Deny_BeePassvpn" against app-identified BeePass VPN traffic.

An internal "DPI Benchmark" methodology document names the three production components underlying TSG's DPI stack and proposes benchmarking each against open-source equivalents: Marsio (DPDK-based packet I/O) for receive/transmit, Sapp ("网络安全开发平台", a high-speed traffic-processing platform) for protocol parsing and flow-table management, and Maat (Hyperscan-class signature engine with Redis-based multi-machine config sync) for pattern scanning.

A September 2023 IIE/CAS-authored test report for a "流量汇接处理子系统" (Traffic Aggregation Processing Subsystem, built on the sapp/durain_master_maat stack) confirms the system is architected to ingest and process a combined 27Gbps of raw traffic from two aggregation points simultaneously: a general "互联网汇聚口" (Internet aggregation port) and a "政务外网汇聚口" (Government Extranet aggregation port) — i.e. the same DPI processing pipeline documented for public-internet censorship is also deployed against China's internal government-network traffic.