Abstract not found

The Internet protocols were designed to emphasize simple routing elements and intelligent hosts. However, there are applications that benefit from allowing hosts to customize or program routers, a concept known as active networking. Since routers are shared, this raises challenges with delivering sufficient flexibility while preserving or improving performance, security, and safety. PLAN (Packet Language for Active Networks) is a language designed for the SwitchWare active network architecture. This architecture comprises active packets containing PLAN programs that invoke service routines over an active OS. PLAN is based on the polymorphic lambda calculus and provides a restricted set of primitives and datatypes that enables reasoning about its impact on network resources based on features of the language design. This paper focuses on the PLAN language with the aim of consolidating a variety of studies that were carried out in the years after its introduction in 1998. These studies include the requirements for PLAN, its design, programming in PLAN, the specification and theory of PLAN, and its use in networking applications.

We propose using application specific virtual machines (ASVMs) to reprogram deployed wireless sensor networks. ASVMs provide

We present SNAP (Safe and Nimble Active Packets), a new scheme for programmable (or active) packets centered around a new lowlevel packet language. Unlike previous active packet approaches, SNAP is practical: namely, adding significant flexibility over IP without compromising safety and security or efficiency. In this paper we show how to compile from the well-known active packet language PLAN [7] to SNAP, showing that SNAP retains PLAN's flexibility; give proof sketches of its novel approach to resource control; and present experimental data showing SNAP attains performance very close to that of a software IP router. Keywords---Active networks, active packets, capsules, resource control. I.

Active Networks promise greater #exibility than current networks, but threaten safety and securityby virtue of their programmability.

. Existing research into active networking has addressed the design and evaluation of programming environments. Testbeds have been implemented on traditional operating systems, deferring issues regarding resource control. This paper describes the architecture, resource models and prototype implementation of the Resource Controlled Active Network Environment (Rcane). Rcane supports an active network programming model over the Nemesis Operating System, providing robust control and accounting of system resources, including CPU and I/O scheduling, and garbage collection overhead. It is thus resistant to many classes of denial of service (DoS) attack. 1 Introduction Adding programmability to a network greatly increases its flexibility. However, with this flexibility comes greater complexity in the ways that network resources, including CPU, memory and bandwidth, may be consumed by end-users. In a traditional network, the resources consumed by an end-user at a network node are rou...

Current routing protocols are monolithic, specifying the algorithm used to construct forwarding tables, the metric used by the algorithm (generally some form of hop count), and the protocol used to distribute these metrics as an integrated package. The Flexible Intra-AS Routing Environment (FIRE) is a link-state, intra-domain routing protocol that decouples these components. FIRE supports run-time-programmable algorithms and metrics over a secure link-state distribution protocol. By allowing the network operator to dynamically reprogram both the properties being advertised and the routing algorithms used to construct forwarding tables, FIRE enables the development and deployment of novel routing algorithms without the need for a new protocol to distribute state. FIRE supports multiple concurrent routing algorithms and metrics, each constructing separate forwarding tables. By using operator-specified packet filters, separate classes of traffic may be routed using completely different routing algorithms, all supported by a single routing protocol. This paper

PLAN (Packet Language for Active Networks) [4] is a highly flexible and usable active packet language, whereas SNAP (Safe and Nimble Active Packets) [11] offers significant resource usage safety and achieves much higher performance compared to PLAN, but at the cost of flexibility and usability. Ideally, we would like to combine the good properties of PLAN with those of SNAP. We have achieved this end by developing a compiler that translates PLAN into SNAP. The compiler allows us to achieve the flexibility and usability of PLAN, but with the safety and efficiency of SNAP. In this paper, we describe both languages, highlighting the features that require special compilation techniques. We then present the details of our compiler and experimental results to evaluate our compiler with respect to code size.

While there has already been significant research in support of openness and programmability in networks, this paper argues that there remains a need for generic support for the integrated development, deployment and management of programmable networking software. We further argue that this support should explicitly address the management of run-time reconfiguration of systems, and should be independent of any particular programming paradigm (e.g. active networking or open signaling), programming language, or hardware/ operating system platform. In line with these aims, we outline an approach to the structuring of programmable networking software in terms of a ubiquitously applied software component model that can accommodate all levels of a programmable networking system from low-level system support, to in-band packet handling, to active networking execution environments to signaling and coordination.

Active Networking adds programmability to the elements of the network, most aggressively by using programmable packets, or capsules. ANTS [1, 2] and PLANet [3, 4] are the most mature examples of capsule-based systems, both having been publicly available for several years. This paper presents our experience with these systems and the lessons they hold for the future of capsule-based Active Networking. The paper focuses on four key issues: flexibility, performance, security, and usability. We consider how ANTS and PLANet address these issues, noting that despite substantial surface differences, both systems identify similar key problems and use closely related solutions. Based on our experience with these systems we conclude that capsule-based systems can achieve useful levels of flexibility, performance, and usability. Many aspects of security can also be adequately addressed, but some important problems related to denial of service remain as open problems. Keywords: Activ...