The 'serial-2' directory combines the 'serial-1' data with relationships inferred from Ark traceroute data, and multi-lateral peering https://catalog.caida.org/paper/2013_inferring_multilateral_peering. To do this we first infer which AS owns each router independent of the interface addresses observed at that router. The ownership inferences are based on IP-to-AS mapping derived from public BGP data, list of peering prefixes from PeeringDB, and the previously inferred business AS relationships. Then we convert the observed IP path into an AS path using the router ownership information (rather than mapping each observed IP to AS directly) and retain the first AS link in the resulting path for the AS graph. The as-rel files contain p2p and p2c relationships. The format is: ||-1 ||0| We disabled public access to 2020-02 and 2020-03 data since some of the links were not calculated correctly, therefore producing errors in customer cone and ranks ------------------------ Acceptable Use Agreement ------------------------ https://www.caida.org/about/legal/aua/public_aua/ When referencing this data (as required by the AUA), please use: The CAIDA AS Relationships Dataset, https://www.caida.org/catalog/datasets/as-relationships/ Also, please, report your publication to CAIDA (https://www.caida.org/catalog/datasets/publications/report-publication).