Routing Under the Hood: Analysing the Impact of Growing CDNs on Network Paths and Anti-Censiorship Approaches

Due to proliferation of CDNs with edge networks, the known hierarchical model of the Internet is gradually changing. Very recently, it has been demonstrated that CDNs have become the part of the Internet core [5]. There are various attempts by researchers to map the ecosystem of big giants like Google, Akamai and Netflix. However, very little attention has been given to how a regular Internet client perceives from the CDN hosted websites. This had direct impact on anti-censorship approaches which rely on web content for their success full operation. In this research project, we first quantify that for a regular Internet user what fraction of Alexa top 1000 websites are located inside/outside its own country. We observe that significant fraction of websites are hosted within the nation. For example, > 80% Alexa top 1000 websites are located inside the Saudi Arabia. We used a popular active geolocation technique, multilateration, for locating the websites. To do so, we implemented multilateration with some modifications suited for our research goals. The general principle behind multilateration is to first find delay between a target node (which needs to geolocated) and a set of reference nodes (whose locations are known apriori). Later, these dalay measurements are converted to approximate distances between the target and the reference nodes. Keeping refernce nodes as centeres and distnces as radii, disks are drwan on the earth’s map, possibly yielding an intersection area, having the target inside it.