Resource Controlled Active Network Elements (RCANE)

主动网络的高级应用需要支持健壮的可配置服务质量(Qos)，并且还需要防止或减轻对安全的复杂的“拒绝服务”攻击。主动网络中一个尚未解决的主要问题是将应用需求映射到分布式资源复用策略中。因为这个问题也困扰着互联网社区(即IP电话、RSVP等)解决方案将对主动式网络之外的网络社区产生广泛而直接的影响。Penn/Bellcore SwitchWare主动式网络项目使用编程语言限制来平衡灵活性、安全性、可用性和性能。与操作系统强制的内存保护不同，编程语言方法可以被视为限制可以由程序生成的地址。这种方法的优点是，某些限制可以在编译时一次强制执行，而不是在运行时重复执行。此外，诸如ML之类的编程语言技术提供了强大的类型检查，这是自动检查程序行为的关键。SwitchWare项目使用Caml-lite ML方言构建了一个Active Bridge和适用于封装的Active Networks(PLAN)的超轻量级编程语言。剑桥复仇女神操作系统支持“软”的实时连续媒体流量。为了避免Qos串扰，它在单点(系统中可能的最低层)执行处理器多路传输，因此即使很大一部分中断处理程序执行也是在调度程序控制下执行的。Nememsis是一个可运行的单地址空间操作系统，通过虚拟地址权限提供保护。Nemsis上的协议是垂直结构的，这意味着应用程序负责它们自己的协议处理所涉及的资源，使用默认的共享库或私有网络。资源受控的主动网元(RCANE)可以通过SwitchWare和Nemsis的合成来构建。这一综合将需要：(1)扩展由编程语言存根管理的Nemsis的Qos管理；(2)支持Nemisis下的Caml-lite；(3)开发用于指定Qos的CAML支持；以及(4)开发对基于多种资源(例如，CPU周期、实际内存、网络带宽)的协同调度的健壮支持。这种共同调度尤其与主动网络相关，其中新资源被暴露给网元的用户。RCANE将生产一种新颖的主动网元，能够支持多媒体流量的服务质量，并限制或抵抗多种形式的拒绝服务攻击，包括“接收活锁”攻击和TCPSYN-ACK攻击。这两个研究小组有广泛的相似兴趣，在实验系统工作方面有卓越的传统，以及合作、人员交流和协作的历史。RCANE是为活动网络元素提供安全、受控的虚拟化的独特机会。这项提案要求为这一合作努力的美国(宾夕法尼亚)部分提供资金；剑桥大学正在申请来自欧洲类似国家科学基金会的资金。

Advanced applications of Active Networks require support for robust configurable Quality of Service (QoS), and to also prevent or mitigate sophisticated "denial of service" attacks on security. A major unsolved problem for active networks is mapping application requirements into a distributed resource multiplexing strategy. Since this problem bedevils the Internet community as well (viz., IP Telephony, RSVP, etc.) a solution would have broad and immediate impact on the networking community beyond Active Networks.The Penn/Bellcore SwitchWare active networks project uses programming-language restrictions to balance flexibility, security, usability and performance. In contrast to operating system enforced memory protection, the programming language approach can be viewed as restricting the addresses which can be generated by programs. The advantage of this approach is that some restrictions can be enforced once, at compilation time, versus repeatedly at run-time. In addition, programming language technologies such as ML provide strong type-checking, a key to automated checks of program behavior. The SwitchWare project has used the Caml-lite ML dialect to build an active bridge and an ultralightweight Programming Language for Active Networks (PLAN) appropriate for capsules.The Cambridge Nemesis Operating System supports "soft" real-time continuous media traffic. To avoid QoS crosstalk, it performs processor multiplexing at a single point, the lowest possible layer in the system, so that even a large portion of interrupt handler execution is performed under scheduler control. Nemesis is anoperational single-address space operating system, providing protection by means of virtual-address permissions. Protocols on Nemesis are "vertically-structured", meaning that applications are responsible for resources involved in their own protocol processing, using either default shared libraries or privatelibraries.Resource Controlled Active Network Elements (RCANE) can be constructed with a synthesis of SwitchWare and Nemesis. This synthesis will entail: (1) extending the QoS management of Nemesis to be managed byprogramming language stubs; (2) supporting Caml-lite under Nemesis; (3) developing Caml support for specifying QoS; and (4) developing robust support for co-scheduling based on multiple resources, e.g.,CPU cycles, real memory, network bandwidth. This co-scheduling is particularly relevant to Active Networks, where new resources are exposed to users of the network element. RCANE will produce a novelactive network element able to support QoS for multimedia traffic and limit or resist denial-of-service attacks of many forms, including "receive-livelock" and TCP SYN-ACK attacks.The two research groups have broadly similar interests, a tradition of excellence in experimental systems work, and a history of cooperation, personnel exchanges and collaborations. RCANE is a unique opportunityto provide secure, controlled virtualization of active network elements. This proposal requests funds for the U.S. (Penn) portion of this collaborative effort; Cambridge is applying for funds from European analogues of the National Science Foundation.