Traffic smoothing for delivery of online VBR media streams is one of the most important problems in designing multimedia systems. Given available client buffer and a window-sliding size, conventional approaches try to reduce bandwidth allocated in each window. However, they can not lead to the minimization of bandwidth allocated for transmitting entire stream. Although a window-sliding approach was introduced to further reduce the bandwidth allocated recently [21], it was computational costly. In this paper, an effective and efficient online traffic-smoothing scheme is proposed. Different from the conventional static window-sliding approaches, our approach dynamically decides the suitable window-sliding size to online smooth the bursty traffic. Then, an aggressive workahead scheme is applied in transmitting entire stream. By examining different media streams, our approach has small bandwidth, high bandwidth utilization and small computation cost. Considering the online transmission of...