The Effects of Inter-packet Spacing on the Delivery of Multimedia Content

Streaming multimedia content with UDP has become increasingly popular over distributed systems such as the Internet. However, because UDP does not possess any congestion-control mechanism and most best-effort traffic is served by the congestion-controlled TCP, UDP flows steal bandwidth from TCP to the point that TCP flows can starve for network resources. Furthermore, such applications may cause the Internet infrastructure to eventually suffer from congestion collapse because UDP traffic does not selfregulate itself. To address this problem, next-generation Internet routers will implement active queue-management schemes to punish malicious traffic, e.g., non-adaptive UDP flows, and to the improve the performance of congestioncontrolled traffic, e.g., TCP flows. The arrival of such routers will cripple the performance of today’s UDP-based multimedia applications. So, in this paper, we introduce the notion of inter-packet spacing with control feedback to enable these UDP-based applications to perform well in the next-generation InterThis work was supported by the U.S. Dept. of Energy through Los Alamos National Laboratory contract W-7405-ENG-36, by the U.S. Dept. of Energy LDRD-ER Grant 2000023, and the Los Alamos Computer Science Institute. Any opinions, findings, and conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the U.S. Dept. of Energy, Los Alamos National Laboratory, or the Los Alamos Computer Science Institute. This paper is LA-UR 01-0904. net while being adaptive and self-regulating. When compared with traditional UDP-based multimedia streaming, we illustrate that our counterintuitive, interpacket-spacing scheme with control feedback can reduce packet loss by 90% without adversely affecting delivered throughput.