During the June 2009 blocking of BBC Persian in Iran, the BBC observed a more-than-fourfold increase in traffic to its BBC Persian TV Internet live stream, with geographic IP lookups confirming the majority of streaming originated from inside Iran. The BBC deployed Psiphon web-proxy nodes — chosen over alternatives because they required no executable installation on the user's PC and could be hosted by a trusted third party — promoted via email newsletters, Twitter, Facebook, and on-air announcements.

The BBC's Geostats prototype (2010) detects censorship events by normalizing hourly traffic from two sources — a web-bug-based Livestats API and approximately 30GB/day of uncompressed Akamai streaming logs — alerting when traffic deviates ±60% from a rolling historical average keyed to hour-of-day and day-of-week. A key limitation identified is that CDN log files arrive up to 24 hours behind real-time, preventing timely detection of live blocking events.

§2.2–§2.3 evaluation

The BBC has distributed international audio and video through Akamai CDN since 2003 using URLs that do not include bbc.co.uk, making URL and IP-based blocking harder than targeting *.bbc.co.uk directly. However, individual Akamai edge machines have been blocked in China, causing thousands of co-hosted websites to become collaterally unavailable, illustrating the concentration risk when many services share CDN IP space.

§4.2 defense

During the December 2010 Nobel Peace Prize ceremony blocking in China, of two Psiphon nodes brought online for the BBC English News site, one was blocked almost immediately while the other remained available throughout the weekend, serving 387 logins on the ceremony day with no direct promotional channel available. A non-BBC-branded live-stream page promoted via a bit.ly URL released one hour before the ceremony received 4,236 clicks, with approximately 50% from China, accounting for about one-third of total stream viewers.

§3.3 deployment

BBC Chinese's multi-channel Psiphon promotion — radio broadcasts three times daily with additional trails, daily email newsletters, and ad hoc tweets — allowed its service to reach page-view parity with BBC Persian's established Psiphon deployment within eight weeks of launch in September 2010. Separately, a third-party BBC Persian iPhone app using full-text RSS feeds received over 50% of its downloads from inside China, demonstrating that syndicated full-text content distributed across multiple third-party sites and apps is difficult for censors to enumerate and block.

§3.2, §4.3 deployment

The June 2025 Iran shutdown—carried out during the Iran-Israel war beginning ~June 19—did not use BGP route withdrawals as in 2019. Instead, authorities applied service-level restrictions at the national border: DNS poisoning of foreign destinations, protocol whitelisting permitting only pre-approved domestic services, and DPI to block circumvention-tool traffic. Iran's international traffic fell roughly 90% while the country's BGP routes remained advertised, making the shutdown invisible to BGP-based monitoring systems. OONI measurement volume, which totalled 121,333 in June 2025, collapsed to under 200 submissions on June 19-20.

2025-iran-shutdown-measurement Executive Summary / §2 dpidns-poisoningport-blockingip-blocking

Chinese users treat full proxy/VPN (Shadowsocks, V2Ray/Clash, commercial VPNs) as the '终极大杀器' (ultimate solution) for bypassing GitHub DNS poisoning, implying that lighter-weight DNS-only fixes fail in some network environments where the censor adds firewall-layer blocking beyond DNS.

2026-anon-6-github-dns §3 使用代理或 VPN dns-poisoningip-blocking

Rule-based proxy tools (Clash, Shadowsocks, V2Ray) are documented as the most reliable solution for accessing GitHub from China, with split-tunneling rules routing only GitHub traffic through the proxy while keeping domestic traffic on the direct path. Git command-line tools require explicit proxy configuration (git config --global http.proxy http://127.0.0.1:7890) to route clone/push operations, as they do not inherit system proxy settings automatically.

2026-anon-github-2026-6-dns §方法二 dns-poisoningip-blocking

The GFW blocks GitHub via DNS poisoning across at least four domains — github.com, assets-cdn.github.com, github.global.ssl.fastly.net, and raw.githubusercontent.com — causing connection timeouts and page-load failures for mainland China users. The block is persistent as of February 2026, affecting both browser access and command-line git operations.

2026-anon-github-2026-6-dns Introduction / §方法一 dns-poisoningip-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

Article 19 documents that Iran combines technical filtering with formal coercion of major foreign platforms (including Telegram, Instagram, and WhatsApp) to comply with content removal orders under threat of full blocking. The report notes that Iran's 2022 Women Life Freedom protests accelerated platform blocking when foreign operators refused compliance, demonstrating that the censorship system operates in two modes: coerce-and-allow for compliant platforms, block for non-compliant ones. Domain fronting via these platforms is therefore subject to sudden revocation if political conditions change.

2026-article19-tightening-the-net §6 ip-blockingdns-poisoningthrottling