Networks at all levels are limited by the export-bandwidth. With the popularity of Internet and its applications, Network is in face of the pressure from expansion. Although it can satisfy the bandwidth requirement in peaks, it will usually result in additional cost of facility upgrade and more expensive rental charge of bandwidth. Based on the tidal characteristics of bandwidth utilization, this paper proposed an adaptive algorithm of dynamic bandwidth allocation. In this algorithm, multiple levels of bandwidth and Quality-of-Level are configured and an alerting factor is introduced. Meanwhile, early warning information of bandwidth expansion can be provided additionally. Experiments are conducted to prove the correctness and effectiveness of the algorithm.
