CBF: LOOK-UP PROTOCOL FOR DISTRIBUTED MULTIMEDIA OBJECTS IN PEER-TO-PEER OVERLAY NETWORKS

Various types of applications take usage of multimedia objects like music and movies. Multimedia objects are distributed in peer-to-peer (P2P) overlay networks since the objects are downloaded and personalized in computers, mainly personal computers interconnected with the Internet. An application would like to take some service of a target object. A target peer is a peer which can manipulate a target object. First, the application has to find target peers which can support enough quality of service (QoS) of target multimedia objects. Due to the scalability and variety of peers in P2P overlay networks, it is difficult, possibly impossible to maintain a centralized directory showing in which peer each object is distributed. In this paper, we newly take an acquaintance approach where each peer maintains its acquaintance peers. An acquaintance peer of a peer p is a peer whose service the peer p knows and with which the peer p can directly communicate in P2P overlay networks. We discuss types of acquaintance relations of peers with respect to what objects each peer holds, is allowed to manipulate, and can grant access rights on. In addition, we discuss a new type of flooding algorithm named charge-based flooding (CBF) algorithm to find target peers based on charge and acquaintance concepts so that areas in P2P overlay networks where target peers are expected to exist are more deeply searched. We evaluate the charge-based flooding (CBF) algorithm compared with a traditional TTL-based flooding algorithm in terms of the number of messages transmitted in networks.