HFT Stuttgart - Univ. of Applied Sciences Tongji/Yale University Ericsson NeuStar Tongji University Tongji University The Content Delivery Networks Interconnection (CDNI) framework [RFC6707] defines a set of protocols to interconnect CDNs, to achieve multiple goals such as extending the reach of a given CDN to areas that are not covered by that particular CDN. One component that is needed to achieve the goal of CDNI described in [RFC7336] is the CDNI Request Routing Footprint & Capabilities Advertisement interface (FCI). [RFC8008] defines precisely the semantics of FCI and provides guidelines on the FCI protocol, but the exact protocol is explicitly outside the scope of that document. In this document, we follow the guidelines to define an FCI protocol using the Application-Layer Traffic Optimization (ALTO) protocol.