Active networks are a novel approach to network architecture in which the switches of the network perform customized computations on the messages flowing through them. This approach is motivated by both lead user applications, which perform user-driven computation at nodes within the network today, and the emergence of mobile code technologies that make dynamic network service innovation attainable. In this paper, we discuss two approaches to the realization of active networks and provide a snapshot of the current research issues and activities. Introduction – What Are Active Networks? In an active network, the routers or switches of the network perform customized computations on the messages flowing through them. For example, a user of an active network could send a “trace ” program to each router and arrange for the program to be executed when their packets are processed. Figure 1 illustrates how the routers of an IP

We present a novel approach to building and deploying network protocols. The approach is based on mobile code, demand loading, and caching techniques. The architecture of our system allows new protocols to be dynamically deployed at both routers and end systems, without the need forcoordination and without unwanted interaction between co-existing protocols. In this paper, we describe our architecture and its realization in a prototype implementation. To demonstrate how to exploit our architecture, we present two simple protocols that operate within our prototype to introduce multicast and mobility services into a network that initially lacks them. 1

Introduction As network connectivity grows throughout the world, the uses of the network also grow. The current network infrastructure cannot and does not keep up with this increase in protocols. We believe that the "Active Networks" approach will help to deal with this problem. Active Networks are those networks in which a node of the network can undergo state changes and can provide information about its current state through execution of programs. Thus, it becomes possible to deploy a new protocol by loading it into a switch or for a packet to attempt to find an optimal route by discovering the state of the switch through which it is currently traveling. In the SwitchWare architecture for active networks, each node is capable of executing programs written in Caml, a dialect of ML. 1.1 Problem Statement We see several problems with existing networking technologies, specifically the Internet technology. First, as the Internet has moved from an experimental n

This paper describes an operating system interface for active routers. This interface allows code loaded into active routers to access the router's memory communication and computational resources on behalf of different packet flows. In addition to motivating and describing the interface the paper also reports our experiences implementing the interface in three different OS environments: Scout the OSSit, and the exokernel.

The term agent comes from greek ‘agein’, which means to drive or to lead. Today the term agent denotes something that produces or is capable of producing an effect. It can be a chemically,

A key challenge facing wireless networking is to utilize the spectrum as efficiently as possible given current channel conditions and in the most effective way for each application. This is difficult to achieve with existing wireless devices because physical layer functionality is fixed, while channel conditions and applications can change rapidly. Instead, we argue that RadioActive networks, an adaptable wireless network architecture which draws on the strengths of software radios and active networks, are needed to meet this challenge. Active networks provide a framework for programming network services, and software radios extend this programmability into the physical layer. We believe that this approach will offer significant improvements in functionality and performance over today's wireless networks because it is no longer necessary to design a priori with pessimistic assumptions that describe worst case conditions. In this paper, we outline our vision, the opportunities it afford...

alien: A Generalized Computing Model of Active Networks David Scott Alexander Jonathan M. Smith Active Networks are networks whose actions may be changed during operation either by introducing new code into the routers (active extensions) or by executing code contained in a packet passing through the switch (active packets). This ability to make changes is expected to ease deployment of new or modified protocols, allow support for uncommon protocols, ease network experimentation, and improve performance in those situations in which quick response to local information is crucial. To maintain security of the system, there must be some restrictions on what code can be executed by any given user. In alien, we have taken the Caml language and restricted it. On this base, we have architected and built a system capable of loading active extensions and executing active packets. We have used this system to measure performance characteristics of each approach. We built two primary experiments: ...

A capsule-oriented active network transports capsules containing code to be executed on the network nodes that they pass through. This approach makes networks more extensible by allowing new networking protocols to be deployed and used without any changes to the underlying network infrastructure. This thesis project describes the design, implementation, and evaluation of a high-performance practical active network node that can serve as a testbed for research into active network performance and resource management issues. Nodes provide resources to executing capsules containing Intel ix86 object code. Although the current implementation does not yet provide safety or interoperability, the results of experiments performed on the system implemented for this thesis indicate that an active network architecture may be able to provide significant flexibility while only incurring a small performance overhead relative to traditional networks. Thesis Supervisor: M. Frans Kaashoek Title: Associa...

This report presents a snap shot of work in progress regarding the active network research at Lancaster University.

In this paper we argue that content distribution in the face of censorship is a compelling and feasible application of active networking. In the face of a determined and powerful adversary, every fixed protocol can become known and subsequently monitored, blocked, or its member nodes identified and attacked. Frequent and diverse protocol change is key to allowing information to continue to flow. Typically, decentralized and locally-customized protocol evolution is also an important aspect in providing censor-resistance.