@inproceedings{gigis2021seven,
author = {Gigis, Petros and Calder, Matt and Manassakis, Lefteris and Nomikos, George and Kotronis, Vasileios and Dimitropoulos, Xenofontas and Katz-Bassett, Ethan and Smaragdakis, Georgios},
title = {Seven Years in the Life of Hypergiants’ Off-Nets},
booktitle = {ACM SIGCOMM 2021},
year = {2021},
month = {August},
abstract = {Content Hypergiants deliver the vast majority of Internet traffic to end users. In recent years, some have invested heavily in deploying services and servers inside end-user networks. With several dozen Hypergiants and thousands of servers deployed inside networks, these off-net (meaning outside the Hypergiant networks) deployments change the structure of the Internet. Previous efforts to study them have relied on proprietary data or specialized per-Hypergiant measurement techniques that neither scale nor generalize, providing a limited view of content delivery on today's Internet.

In this paper, we develop a generic and easy to implement methodology to measure the expansion of Hypergiants' off-nets. Our key observation is that Hypergiants increasingly encrypt their traffic to protect their customers' privacy. Thus, we can analyze publicly available Internet-wide scans of port 443 and retrieve TLS certificates to discover which IP addresses host Hypergiant certificates in order to infer the networks hosting off-nets for the corresponding Hypergiants. Our results show that the number of networks hosting Hypergiant off-nets has tripled from 2013 to 2021, reaching 4.5k networks. The largest Hypergiants dominate these deployments, with almost all of these networks hosting an off-net for at least one -- and increasingly two or more -- of Google, Netflix, Facebook, or Akamai. These four Hypergiants have off-nets within networks that provide access to a significant fraction of end user population.},
url = {http://approjects.co.za/?big=en-us/research/publication/seven-years-in-the-life-of-hypergiants-off-nets/},
pages = {516-533},
}