# Nautilus: A Framework for Cross-Layer Cartography of Submarine Cables and IP Links

## TL;DR

Nautilus is a framework that maps IP links to submarine cables using public data and cartographic techniques, improving understanding of how cable failures impact Internet connectivity.

## Contribution

It introduces Nautilus, a novel cross-layer mapping framework that links IP traffic to submarine cables with high coverage and confidence scores.

## Key findings

- Maps 91% of active cables with over 4 million IP links.
- Validates mappings through cable failure analysis and traceroute measurements.
- Provides a tool for assessing the impact of cable disruptions on the Internet.

## Abstract

Submarine cables constitute the backbone of the Internet. However, these critical infrastructure components are vulnerable to several natural and man-made threats, and during failures, are difficult to repair in their remote oceanic environments. In spite of their crucial role, we have a limited understanding of the impact of submarine cable failures on global connectivity, particularly on the higher layers of the Internet. In this paper, we present Nautilus, a framework for cross-layer cartography of submarine cables and IP links. Using a corpus of public datasets and Internet cartographic techniques, Nautilus identifies IP links that are likely traversing submarine cables and maps them to one or more potential cables. Nautilus also gives each IP to cable assignment a prediction score that reflects the confidence in the mapping. Nautilus generates a mapping for 3.05 million and 1.43 million IPv4 and IPv6 links respectively, covering 91% of all active cables. In the absence of ground truth data, we validate Nautilus mapping using three techniques: analyzing past cable failures, using targeted traceroute measurements, and comparing with public network maps of two operators.