ITR: Collaborative Research: Resource Allocation and Denial of Service Prevention in Active Networks

ITR：协作研究：主动网络中的资源分配和拒绝服务预防

• 批准号: 0081360
• 负责人: Scott Nettles
• 金额: $ 41.77万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0081360&HistoricalAwards=false
• 关键词: ITR; Collaborative; Research; Resource; Allocation

The Internet is used by a rapidly expanding and changing set of applications. The need for the network to evolve and even to provide application specific processing is significant. However the current network infrastructure is hard to evolve and does not readily support customizability. The goal of Active Networking [21, 3, 2] is to facilitate this evolution and customization by making the network infrastructure programmable. One way of adding programability is to allow code to be down-loaded into the routers, thus enabling the addition or modification of services. A more radical approach is to allow the packets themselves to carry programs to be executed selectively on the network's routers. Among other issues, these two approaches increase the possibility of denial of service attacks whereby a user places excessive demands on network resources in order to deny access to another user. However, they also enable new approaches to handling such attacks and to addressing the general problem of allocating resources within the network.The proposed research focuses on issues involving programmable, or active, packets. Active packets facilitate denial of service attacks in several ways. First, unlike conventional data transport packets, an active packet may require processor cycles and memory at the routers beyond those needed to simply forward the packet. Second, in general, the execution of an active packet at a router may cause more than one active packet to be transmitted from the router. Such behavior is useful, since it allows a packet to fan out across the network, but it is potentially dangerous since it can lead to an exponential growth in the resources used by a single initial packet. Experience with active packet-based systems [9, 8, 23, 22, 24] suggests that denial of service is the single biggest obstacle which must be overcome before such systems are feasible.The proposed research tackles this problem along various fronts. First, the researchers propose to design packet programming languages that make some types of behavior intrinsically impossible. For example, in PLAN [9], packet programs are guaranteed to terminate and thus can never use an un-bounded number of router cycles. The researchers will explore tradeoffs between restricting behavior in terms of resource requirements and limiting the expressibility and thus the flexibility of active packets. However, not all potentially harmful behaviors can be eliminated in this manner. Thus, on a second front, the researchers will consider mechanisms that explicitly account for a packet's resource usage in the network. For example, each packet may carry a resource bound, which is decremented as resources are used, and which triggers termination when the bound is used up. The proposed research combines both implicit and explicit mechanisms for controlling resource usage, with algorithms to control the flow of traffic into the network to decrease the likelihood of denial of service. More generally, one can envisage assessing costs to active packets that execute on congested resources. Thus, on a third front, the researchers propose to investigate mechanisms based on congestion costs to achieve more efficient resource allocations and how they can be facilitated via active packets.Three methodologies will be used to validate proposed solutions. First, the researchers will draw on mathematical modeling to motivate the benefits and investigate the characteristics of the proposed solutions. Second, the researchers will leverage expertise and past work on implementing active networks to demonstrate what is feasible to build, and explore the constraints each solution will place on eventual applications. Finally, the researchers will use network simulation to investigate systems on a scale not achievable on the experimental testbeds.

互联网被快速扩展和变化的应用程序所使用。网络发展甚至提供特定于应用程序的处理的需求是巨大的。然而，当前的网络基础设施很难发展，并且不容易支持可定制性。主动网络 [21,3,2] 的目标是通过使网络基础设施可编程来促进这种演进和定制。增加可编程性的一种方法是允许将代码下载到路由器中，从而能够添加或修改服务。更激进的方法是允许数据包本身携带要在网络路由器上选择性执行的程序。除其他问题外，这两种方法增加了拒绝服务攻击的可能性，即用户对网络资源提出过多的要求，以拒绝另一个用户的访问。然而，它们还提供了新的方法来处理此类攻击并解决网络内资源分配的一般问题。拟议的研究重点是涉及可编程或活动数据包的问题。活动数据包以多种方式促进拒绝服务攻击。首先，与传统的数据传输分组不同，活动分组可能需要路由器处的处理器周期和存储器，超出简单转发分组所需的那些。其次，一般来说，在路由器处执行活动分组可能导致从路由器发送多于一个活动分组。这种行为很有用，因为它允许数据包在网络上散开，但它也有潜在的危险，因为它可能导致单个初始数据包使用的资源呈指数增长。基于主动分组的系统的经验[9,8,23,22,24]表明拒绝服务是此类系统可行之前必须克服的最大障碍。本文提出的研究从各个方面解决了这个问题。首先，研究人员建议设计数据包编程语言，使某些类型的行为本质上不可能。例如，在 PLAN [9] 中，包程序保证终止，因此永远不能使用无限数量的路由器周期。研究人员将探索在资源需求方面限制行为与限制可表达性以及活动数据包的灵活性之间的权衡。然而，并不是所有潜在的有害行为都可以通过这种方式消除。因此，在第二方面，研究人员将考虑明确考虑网络中数据包资源使用情况的机制。例如，每个分组可以携带资源界限，该资源界限随着资源的使用而递减，并且当该界限用完时触发终止。所提出的研究结合了控制资源使用的隐式和显式机制以及控制进入网络的流量的算法，以降低拒绝服务的可能性。更一般地，可以设想评估在拥塞资源上执行的活动数据包的成本。因此，在第三个方面，研究人员建议研究基于拥塞成本的机制，以实现更有效的资源分配，以及如何通过活动数据包促进它们。将使用三种方法来验证所提出的解决方案。首先，研究人员将利用数学模型来激发优势并研究所提出的解决方案的特征。其次，研究人员将利用专业知识和过去实施主动网络的工作来展示构建的可行性，并探索每种解决方案对最终应用的限制。最后，研究人员将使用网络模拟来研究实验测试台上无法实现的规模的系统。