An Investigation of Inter-Domain Control Aggregation Procedures

Current Quality of Service models such as those embod-ied in the Differentiated Services proposal, rely on data path aggregation to achieve scalability. Data path aggregation bundles into a single aggregate multiple flows with the same quality requirements, hence decreasing the amount of state to be kept. A similar scalability concern exists on the con-trol path, where the state required to account for individual reservations needs to be minimized. There have been sev-eral proposals aimed at control path aggregation, and the goal of this paper is to expand on these works in an attempt to gain a better understanding of the various parameters that influence the efficiency of different approaches. In par-ticular, we focus on inter-domain control aggregation, and compare an Autonomous System (AS) sink-tree based ap-proach with two examples of a shared AS segment based approach, in terms of the amount of state kept, both per AS and per edge router. Our main contributions are in pro-viding a greater understanding into the design of efficient control path aggregation methods. 1