Scalable and topology-aware application layer multicast architecture

Various ALM (Application Layer Multicast) mechanisms have been suggested to remove the barriers that block deployment of IP multicast. However, most of ALM mechanisms do not consider host group model, which is not a problematic portion, but advantageous feature of traditional IP multicast in terms of scalability, robustness, security, and transparency. Furthermore those mechanisms build overlay multicast network for data delivery mostly based on simple measurement with a few metrics without directly considering IP network topology. Thus, they might suffer some inefficiency such as long join delay and large control overhead. In this paper, we propose a scheme to take advantages of both IP multicast and ALM, based on two principle design factors. By adopting host group model, our scheme can inherently acquire network topology information used to get rid of inefficiency of application level routing, and to gain additional efficiency for many group members. Also, we exploits topology-awareness to reduce join delay and localize group members so that controls for setting up and maintaining overlay networks can be limited in a domain. Overall network performance is enhanced with our scheme by building overlay network based on performance factors associated with network characteristics using hierarchical structure.