Adaptive Bandwidth Allocation: Concepts and Efficiency for Admission-Controlled Capacity Tunnels

In this paper, we propose mechanisms for an adaptive bandwidth allocation (ABA) based on border-to-border (b2b) bandwidth budgets. These budgets can be considered as virtual capacity tunnels binding a fraction of the network capacity and connecting different network border routers. Unlike MPLS label switched paths or ATM virtual path connections associated with a certain bandwidth, these tunnels support multi-path routing. Moreover, they can be used to implement resilient b2b budget-based network admission control. If static bandwidth allocation (SBA) based on peak-rate traffic assumptions is used to dimension the b2b budgets, fluctuations of the network traffic can lead to underor overprovisioning of network capacity within these budgets. The contribution of this paper is twofold. Firstly, we address this problem by two new ABA mechanisms – complete capacity reassignment (CCR) and selective capacity reassignment (SCR) – which adapt the sizes of the b2b budgets with regard to their current bandwidth requirements. Secondly, we investigate the bandwidth savings potential of these meachanisms by the construction of synthetically shifted but constantly loaded traffic matrices. Though focused on the above two aspects, the study of ABA based on b2b budgets is not finished and further investigations are currently in progress.