An acknowledgement mechanism for reliable application layer multicast

This paper proposes a tree-based acknowledgement mechanism designed for a reliable application layer multicast, called ATACK. The proposed mechanism divides the group members into a hierarchy of logical acknowledgement domains by a self-organized way, and further builds the acknowledgement tree in terms of hierarchical acknowledgement domains. The expected size of the acknowledgement domain is within some fixed range, which promises the efficient acknowledgement and avoids adjusting acknowledgement domains frequently. In each domain, only a part of group members send acknowledgement messages to the corresponding acknowledgement processor according to the error correlation of the ALM delivery tree. Therefore the proposed acknowledgement mechanism can effectively reduce the related load and improves the acknowledgement performance.