A/HRC/35/22 B. Internet exchange points 34. IXPs enable the exchange of Internet traffic between and among networks managed by different providers within a country or region. 61 This form of interconnection prevents local or regional Internet traffic from taking long and circuitous international routes, thus enhancing the speed and efficiency of Internet connectivity. IXPs may be established by Internet infrastructure companies as part of a broader suite of services sold to providers or operated as non-profit or volunteer organizations.62 35. IXPs handle an enormous volume of Internet traffic that may be filtered or intercepted at government request. The growing number of censorship and surveillance incidents involving IXPs indicates that they are major access choke points, even if their precise role is unclear. For example, in 2013, the manner in which access to YouTube was blocked in Pakistan indicated that the platform was filtered by IXPs, rather than ISPs, through a method known as “packet injection”.63 According to a leaked internal memo of a multinational ISP operating in Ecuador, users were unable to access Google and YouTube in March 2014 because the private Association of Internet Providers of Ecuador — which runs two of the major IXPs in the country — was “blocking access to certain Internet websites by request of the national Government”.64 The revelations of mass surveillance conducted by the United States National Security Agency have raised concern among technologists that the agency is intercepting a significant proportion of domestic and foreign Internet traffic by targeting United States IXPs. 65 In September 2016, the world’s largest Internet exchange point, which is based in Germany, challenged legal orders issued by the country’s intelligence agency to monitor international communications transiting through its hub.66 C. Content delivery networks 36. A content delivery network (CDN) is a network of servers strategically distributed around the world to enable the efficient delivery of web pages and other Internet content. Large content producers rely on content delivery networks to reach as many users as quickly as possible.67 A content delivery network stores copies of content hosted on these platforms and redirects a user’s request for such content from the platform’s servers to the servers within its network that are located closest to the user. 68 This process enhances the speed of content delivery, particularly to users located far away from the platform’s servers. Content delivery networks are regarded as an effective safeguard against website blocking; censorship measures targeting servers that host a particular website or platform do not affect the content delivery network’s delivery of copies of the same content to users. 69 Content delivery networks have also become a critical bulwark against network disruptions. The demands of rapid access have incentivized them to invest significant resources in infrastructure and services that can withstand distributed denial-of-service and other malicious attacks.70 61 62 63 64 65 66 67 68 69 70 See www.bgp4.as/internet-exchanges/. Jason Gerson and Patrick Ryan, “A primer on Internet exchange points for policymakers and nonengineers” Social Science Research Network (12 August 2012), p. 10. Zubair Nabi, “The anatomy of web censorship in Pakistan” (2013), p. 4. Katitza Rodriguez, “Leaked documents confirm Ecuador’s Internet censorship machine”, Electronic Frontier Foundation (14 April 2016). Andrew Clement and Jonathan Obar, “Canadian Internet ‘boomerang’ traffic and mass NSA surveillance: Responding to privacy and network sovereignty challenges”, in Law, Privacy and Surveillance in Canada in the Post-Snowden Era, Michael Geist, ed. (University of Ottawa Press, 2015). De Cix, “Information on the lawsuit against the Federal Republic of Germany” (16 September 2016). Geoff Huston, “The death of transit?”, Asia Pacific Network Information Centre (27 October 2016). Vangie Beal, “CDN – Content Delivery Network”, Webopedia. John Holowczak and Amir Houmansadr, “CacheBrowser: bypassing Chinese censorship without proxies using cached content” (2015). Geoff Huston, “The death of transit?”, Asia Pacific Network Information Centre (27 October 2016). 11