TCP-LP: a distributed algorithm for low priority data transfer
TCP-LP: a distributed algorithm for low priority data transfer
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DOI：
10.1109/infcom.2003.1209192
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发表时间：
2003-07
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影响因子：
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通讯作者：
A. Kuzmanovic;E. Knightly
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文献类型：
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作者：
A. Kuzmanovic;E. Knightly
不同业务类别之间的服务优先级划分是未来互联网的重要目标。解决这一问题的传统方法将现有的尽力而为类别视为低优先级类别，并试图开发提供“好于尽力”服务的机制。在本文中，我们探索了相反的方法，并设计了一种新的分布式算法来从网络端点实现低优先级服务(与现有的尽力而为相比)。为此，我们开发了TCP低优先级(TCP-LP)，这是一种分布式算法，其目标是仅利用多余的网络带宽，而不是TCP所针对的带宽的“公平份额”。TCP-LP拥塞控制所独有的关键机制是使用单向分组延迟来指示拥塞，以及一种对TCP透明的拥塞避免策略。我们的仿真结果表明：(1)TCP-LP在很大程度上不会对TCP流量造成干扰；(2)单个和聚合的TCP-LP流都能够成功地利用多余的网络带宽；而且，多个TCP-LP流公平地共享了多余的带宽；(3)即使在存在贪婪的TCP流的情况下，大量的多余带宽也可供低优先级类别使用；(4)当长生命周期的批量数据传输使用TCP-LP而不是TCP时，尽力而为类别中的Web连接的响应时间最高可减少90%。
Service prioritization among different traffic classes is an important goal for the future Internet. Conventional approaches to solving this problem consider the existing best-effort class as the low-priority class, and attempt to develop mechanisms that provide "better-than-best-effort" service. In this paper, we explore the opposite approach, and devise a new distributed algorithm to realize a low-priority service (as compared to the existing best effort) from the network endpoints. To this end, we develop TCP Low Priority (TCP-LP), a distributed algorithm whose goal is to utilize only the excess network bandwidth as compared to the "fair share" of bandwidth as targeted by TCP. The key mechanisms unique to TCP-LP congestion control are the use of one-way packet delays for congestion indications and a TCP-transparent congestion avoidance policy. Our simulation results show that: (1) TCP-LP is largely non-intrusive to TCP traffic; (2) both single and aggregate TCP-LP flows are able to successfully utilize excess network bandwidth; moreover, multiple TCP-LP flows share excess bandwidth fairly; (3) substantial amounts of excess bandwidth are available to low-priority class, even in the presence of "greedy" TCP flows; (4) the response times of web connections in the best-effort class decrease by up to 90% when long-lived bulk data transfers use TCP-LP rather than TCP.