Practical Algorithms of Bandwidth Regulation for Rate-Based Switching

A rate-based switch fabric called smoothed buffer crossbar has been proposed in our recent work. It can provide 100% rate-guaranteed service with only a two-cell buffer at each crosspoint, and can also support best-effort service with an additional bandwidth regulator. However, the widely used max- flow model for bandwidth regulation is neither scalable nor of 100% throughput. In order to evaluate the performance of bandwidth regulator, we first introduce the 100% ideal throughput measurement in this paper. Then we prove that the total arrival average (TAA) algorithm has got this property, which does not happen in the max-flow allocation. Then an O(N) algorithm called proportion scaling allocation (PSA) is presented. Simulations reveal that PSA can deliver nearly 100% throughput even in a frequently changing traffic pattern. As a comparison, both theoretical and experimental evidences are given to show the inefficiency of the max-flow model.