About NetCores

NetCores is a network analysis tool that performs k-core decomposition on Internet topology data to understand the connectivity patterns of Autonomous Systems (AS).

What is k-core Decomposition?

k-core decomposition is a graph analysis technique that assigns each node a "shell index" representing its position in the network's connectivity hierarchy. Nodes with higher shell indices are more central to the network's connectivity.

Reading the charts

• Normalized shell index: the AS's shell index divided by the largest shell index in that month's graph. 1 means the AS is in the innermost core (the max-core). This makes 1998 and 2026 comparable even though the graph got much deeper.
• Shell index: the raw value. The shaded area behind the lines is the maximum shell index of each month.
• Distance to core: how many shells separate the AS from the innermost core; 0 means it is in it.

Snapshots are monthly, so the lines are drawn as steps: a value holds until the next snapshot. The core over time shows how deep the graph is, how many ASes share the innermost core and how many ASes exist in each month.

Data Source

NetCores analyzes AS-relationship data from the Center for Applied Internet Data Analysis (CAIDA). This data represents the peering and transit relationships between Autonomous Systems on the Internet.

AS names come from CAIDA's AS Organizations dataset, refreshed monthly, with short labels for well-known networks.

Analysis Features

• Temporal Analysis: Track how AS connectivity evolves over time
• Normalized Comparisons: Compare ASNs relative to the maximum connectivity in each time period
• IPv4/IPv6 Support: Analyze both IPv4 and IPv6 topology data
• Interactive Visualizations: Explore trends with interactive Plotly charts

Use Cases

Academic Research

NetCores implements methodologies and concepts from the following research papers, developed as a joint collaboration between ITBA (Instituto Tecnológico de Buenos Aires), UC San Diego, CAIDA (Center for Applied Internet Data Analysis), Universidad de Buenos Aires, and CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas).

@article{carisimo:kcores:comcom2019,
title = {Studying the evolution of content providers in IPv4 and IPv6 internet cores},
    journal = {Computer Communications},
    volume = {145},
    pages = {54-65},
    year = {2019},
    issn = {0140-3664},
    author = {Esteban Carisimo and Carlos Selmo and J. Ignacio Alvarez-Hamelin and Amogh Dhamdhere},
    keywords = {Content providers, CDNs, Topology, k-cores}
}

@INPROCEEDINGS{carisimo:kcores:tma2018,  
    author={Carisimo, Esteban and Selmo, Carlos and Alvarez-Hamelin, J. Ignacio and Dhamdhere, Amogh},  
    booktitle={2018 Network Traffic Measurement and Analysis Conference (TMA)},   
    title={Studying the Evolution of Content Providers in the Internet Core},   
    year={2018},  
    pages={1-8}
}