In this paper, we consider adaptive bandwidth allocation (ABA) for capacity tunnels as an effective means for multi-hour network design. Traffic engineering (TE) tunnels established in a network from border-to-border (b2b) can be used not only for route pinning between ingress/egress node pairs but also for efficient implementation of resilient network admission control. If static bandwidth allocation (SBA) based on peak-rate traffic assumptions is used to dimension the b2b tunnels, fluctuations of the network traffic can lead to under- or overprovisioning of network capacity in the tunnels. If ABA is used instead, the tunnel sizes are dynamically adapted to current traffic conditions. The efficient use of network capacity assigned to TE tunnels strongly depends on the structure of these tunnels. The contribution of this paper is an assessment of the bandwidth savings that are achievable with ABA in comparison to SBA for various tunnel structures with different path layouts and load balancing strategies. Our results show that the capacity savings due to ABA depend on the routing and load balancing schemes provisioned in the network and that these savings may be increased by appropriately chosen tunnel implementations. 1

In this paper, we consider configurable capacity tunnels. Static bandwidth allocation (SBA) assigns the network capacity to the tunnels according to the busy hours of their traffic aggregates. At secondary times, their capacity is underutilized and can not be used to accommodate excess traffic of other tunnels. The contribution of this paper is twofold. Firstly, we propose two mechanisms for adaptive bandwidth allocation (ABA) for the tunnels: complete capacity reassignment (CCR) and selective capacity reassignment (SCR). They both adapt the tunnel capacities to the current traffic demands but differ in their implementation, signaling, and configuration complexity. Secondly, we asses the bandwidth savings of ABA vs. SBA in wide area networks where the transfer rates of traffic aggregates fluctuate over time according to busy hours. Our results show that the capacity savings strongly depend on the traffic model and that they may be increased by time-aware routing. 1

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 under- or 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. 1