Archive for the 'Paper' Category

Unintended consequences of submarine cable deployment on Internet routing

Tuesday, December 15th, 2020 by Roderick Fanou

Figure 1: This picture shows a line of floating buoys that designate the path of the long-awaited SACS (South-Atlantic Cable System). This submarine cable now connects Angola to Brazil (Source: G Massala, https://www.menosfios.com/en/finally-cable-submarine-sacs-arrived-to-brazil/, Feb 2018.)

The network layer of the Internet routes packets regardless of the underlying communication media (Wifi, cellular telephony, satellites, or optical fiber). The underlying physical infrastructure of the Internet includes a mesh of submarine cables, generally shared by network operators who purchase capacity from the cable owners [2,11]. As of late 2020, over 400 submarine cables interconnect continents worldwide and constitute the oceanic backbone of the Internet. Although they carry more than 99% of international traffic, little academic research has occurred to isolate end-to-end performance changes induced by their launch.

In mid-September 2018, Angola Cables (AC, AS37468) activated the SACS cable, the first trans-Atlantic cable traversing the Southern hemisphere [1][A1]. SACS connects Angola in Africa to Brazil in South America. Most assume that the deployment of undersea cables between continents improves Internet performance between the two continents. In our paper, “Unintended consequences: Effects of submarine cable deployment on Internet routing”, we shed empirical light on this hypothesis, by investigating the operational impact of SACS on Internet routing. We presented our results at the Passive and Active Measurement Conference (PAM) 2020, where the work received the best paper award [11,7,8]. We summarize the contributions of our study, including our methodology, data collection and key findings.

[A1]  Note that in the same year, Camtel (CM, AS15964), the incumbent operator of Cameroon, and China Unicom (CH, AS9800) deployed the 5,900km South Atlantic Inter Link (SAIL), which links Fortaleza to Kribi (Cameroon) [17], but this cable was not yet lit as of March 2020.

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CAIDA wins Best Paper at ACM SIGCOMM 2018!

Wednesday, August 22nd, 2018 by CAIDA Webmaster

Congratulations to Amogh Dhamdhere, David Clark, Alexander Gamero-Garrido, Matthew Luckie, Ricky K.P. Mok, Gautam Akiwate, Kabir Gogia, Vaibhav Bajpai, Alex Snoeren, and kc claffy, for being awarded Best Paper at SIGCOMM 2018!

The abstract from the paper, “Inferring Persistent Interdomain Congestion“:

There is significant interest in the technical and policy communities regarding the extent,scope, and consumer harm of persistent interdomain congestion. We provide empirical grounding for discussions of interdomain congestion by developing a system and method to measure congestion on thousands of interdomain links without direct access to them. We implement a system based on the Time Series Latency Probes (TSLP) technique that identifies links with evidence of recurring congestion suggestive of an under-provisioned link. We deploy our system at 86 vantage points worldwide and show that congestion inferred using our lightweight TSLP method correlates with other metrics of interconnection performance impairment. We use our method to study interdomain links of eight large U.S. broadband access providers from March 2016 to December 2017, and validate our inferences against ground-truth traffic statistics from two of the providers. For the period of time over which we gathered measurements, we did not find evidence of widespread endemic congestion on interdomain links between access ISPs and directly connected transit and content providers, although some such links exhibited recurring congestion patterns. We describe limitations, open challenges, and a path toward the use of this method for large-scale third-party monitoring of the Internet interconnection ecosystem.

Read the full paper on the CAIDA website.