Abstract. There is an increasing economic desire driven by widespread applications like IPTV or conferencing that a next generation Internet will grant transparent group communication service to all its stationary and mobile users. In this paper, we present a generic approach to inter-domain multicast, which is guided by an abstract, DHT-inspired overlay, but may operate on a future Internet architecture. It is based on the assumptions of a globally available end-to-end unicast routing between resolvable locators, taken from a name space that allows for aggregation. Our protocol design accounts for this aggregation, leading to forward-path forwarding along bidirectional shared distribution trees in prefix space. The scheme facilitates multipath multicast transport, offers fault-tolerant routing, arbitrary redundancy for packets and paths and remains mobility agnostic. We present OASIS, its application to IPv6, and evaluate signaling costs analytically based on its k-ary tree structure.