SP: Collaborative Research: Rapid Evolution of Transport Protocols

互联网是一个巨大的工程成功。至少在过去的十年里，它一直保持着令人兴奋的增长和变化速度，并得到了广泛的应用，使其成为社会结构的一部分。在基础技术和新应用的变化的驱动下，它肯定会继续发展。这种发展得到了大量不同研究的支持，这些研究通常预测未来的需求。在传输协议方面，我们的重点是，未来的协议包括新一代的流媒体协议、高速率下的稳定拥塞控制协议、移动的协议、多宿主和聚合连接协议以及通过对等网络和应用层组播进行的信息传播协议。不幸的是，无论这些研究多么有前途，都很难将这些研究成果应用于全球互联网。今天，操作系统供应商，而不是研究人员，甚至不是产品开发人员，通常必须提供新的传输协议。为了适合部署，这些协议必须能够在长期的逐步采用过程中成功地与已安装的传输基础进行互操作。这一过程既昂贵又耗时。更阴险的是，它有一个激励结构，不鼓励实验和早期采用者。底线是，目前的升级机制可以说是实现许多正在进行的研究工作的好处的限制因素。研究人员建议研究一种新的方法来发展的传输协议，将允许实验人员快速，方便地升级传输协议。它将在现实的互联网环境中这样做，而不太关心安装基础。例如，这将允许GRID社区部署经过精心调整以实现高速率传输的TCP，或者研究拥塞管理器的研究人员可以在大规模和广域范围内对其进行实验。该系统的设想将从根本上不同于今天的独立的终端系统升级，通过允许一个连接的一端升级其他使用不可信的移动的代码。这种“双端”升级模式将通过倾斜激励结构的平衡来鼓励部署有用的协议，从而有利于早期采用者。它将允许研究人员和开发人员直接升级传输协议，而不是通过操作系统供应商间接升级。提议者认为，它有可能使目前其他人正在进行的研究的效益成倍增加。关键的挑战是确定如何通过双端升级实现快速发展的直接愿景，而不否定其实际利益。这是一个困难的任务，因为不可信的移动的代码的使用以前已经在更一般的主动网络领域进行了探索，但成功有限。然而，他们认为，在这一建议的主体，现在是时间为一个协调一致的研究努力的传输协议部署。网络协议理解的新进展（特别是TCP友好性和使用ECN随机数的鲁棒拥塞信令），理解安全语言运行时中的共享和终止问题，以及成熟的语言技术（以Cyclone的形式，一种安全但类似C的语言）-加上一个定义良好的问题域，简化了保护问题-使有效使用不受信任的移动的代码成为一个真实的，尽管具有挑战性，可能性PI拥有所有这些领域的专业知识，沿着建立的研究合作。更广泛的影响。拟议的研究有可能通过真正的多重效应产生广泛影响：它直接有助于实现其他人进行的研究的好处，通过其激励结构促进而不是阻碍升级。在现实环境中试验新传输协议的容易性将降低研究障碍，帮助更多的研究人员（特别是少数机构）更多地基于他们的想法进行竞争，而不是他们能够召集的部署资源水平。研究人员希望这项工作具有很强的教育意义，因为学生和研究人员可以安全地进行实验，而不必担心对网络产生不利影响，即使是在通用的共享机器上。真实的部署，也许是解决真实的问题，可以发生在同学之间，最终只受协议的价值和学生宣传它的能力的限制。

The Internet is a tremendous engineering success. It has sustained a heady rate of growth and changeover at least the past decade and has found broad application that has made it part of the fabric of society.Driven by changes in the underlying technology and by new applications, it is certain to continue evolving.Such evolution is supported by a large and diverse body of research that often anticipates future needs.In the case of transport protocols, our focus, the future holds protocols for a new generation of streamingmedia, stable congestion control at very high rates, mobile, multi-homed and aggregate connections, andinformation dissemination via peer-to-peer networks and application-level multicast-at least.Unfortunately, it is very difficult to move from the results of such research to use in the global Internet,no matter how promising the research. Today, operating system vendors, not researchers nor even productdevelopers, must typically provide new transport protocols. To be suitable for deployment, these protocolsmust be able to successfully interoperate with the installed base of transports during the long period ofgradual adoption. This process is costly and time-consuming. More insidiously, it has an incentive structurethat discourages experimentation and early adopters. The bottom line is that current upgrade mechanismsare arguably the limiting factor in realizing the benefits of many ongoing research efforts.The researcherss propose to investigate a new approach to the evolution of transport protocols that will allow experimenters to quickly and easily upgrade transport protocols. It will do so in a realistic Internet setting and with less concern for the installed base. This would allow, for example, the GRID community to deploya TCP carefully tuned for high-rate transfers, or researchers studying the Congestion Manager to readilyexperiment with it at a large scale and across the wide-area. The system envisioned will fundamentallydiffer from today's independent end-system upgrades by allowing one end of a connection to upgrade theother by using untrusted mobile code. This "dual-end" upgrade model will encourage the deployment ofuseful protocols by tipping the balance of the incentive structure in favor of early adopters. It will encourageexperimentation by allowing researchers and developers to upgrade transport protocols directly, rather thanindirectly via operating system vendors. The proposers believe it has the potential to multiply the benefits of research that is currently being undertaken by others.Intellectual Merit. The key challenge is to determine how it is possible to realize the straightforwardvision of rapid evolution via dual-end upgrades without negating its practical benefits. This is a difficulttask, as the use of untrusted mobile code has been previously explored in the much more general domain ofactive networks, with limited success. However, they argue in the body of this proposal that now is the timefor a concerted research effort on transport protocol deployment. Recent advances in the understanding ofnetwork protocols (specifically TCP friendliness and robust congestion signaling with ECN nonces), understanding of the sharing and termination issues in safe-language runtimes, and maturing language technology (in the form of Cyclone, a safe yet C-like language)-plus a well-defined problem domain that simplifies protection issues-have made the effective use of untrusted mobile code a real, though challenging, possi-bility. The PIs have expertise in all of these areas, along with an established research collaboration.Broader Impacts. The proposed research has the potential to achieve a broad impact by a true multipliereffect: it directly helps to realize the benefits of research that is undertaken by others, encouragingrather than discouraging upgrades by virtue of its incentive structure. The ease of experimenting with newtransport protocols in a realistic setting will lower the research barrier, helping a larger pool of researchers (and particularly minority institutions) to compete more on the basis of their ideas and less on the level of deployment resources they are able to muster. The researchers expect there to be a strong educational component of this work, since students as well as researchers can safely experiment without concern for adversely impacting the network, even on generic, shared machines. Real deployment, perhaps solving real problems, can occur among fellow students, and is ultimately limited only by a protocol's value and the students' ability to publicize it. Thus will students, and researchers, be empowered and motivated.