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

Active networks represent a new approach to network architecture. Routers can perform computations on user data, while packets can carry programs to be executed on routers and possibly change their state. Currently, the research community is divided concerning the usefulness of active networks. On the one hand, active networks provide a much more flexible network infrastructure, with increased capabilities. On the other hand, they are obviously more complex than traditional networks and raise considerable security issues. The purpose of this article is to provide a broad survey on active networks. The first goal is to highlight their efficiency in a variety of applications. After presenting some key points on each application, we discuss some current experimental technologies and assess the usefulness of active networks in congestion control, multicasting, caching, and network management. The second goal is to address the security issues that active networks raise: the proble...

Active networks permit applications to inject programs into the nodes of local and, more importantly, wide area networks. This supports faster service innovation by making it easier to deploy new network services. In this paper, we discuss both the potential impact of active network services on applications and how such services can be built and deployed. We explore the impact by suggesting sample uses and arguing how such uses would improve application performance. We explore the design of active networks by presenting a novel architecture, ants, that adds extensibility at the network layer and allows for incremental deployment of active nodes within the Internet. In doing so, ants tackles the challenges of ensuring that the exibility o ered by active networks does not adversely impact performance orsecurity. Finally, we demonstrate how a new network service may be expressed in ants.

Abstract. Active networks are receiving increasing attention due to their promises of great exibility in tailoring services to applications. This capability stems from the exploitation of network devices whose behavior can be changed dynamically by applications, possibly using technologies and architectures originally conceived for mobile code systems. Notwithstanding the promises of active networks, real-world applications that clearly bene t by them are still missing. In this work we describe the design of a videoconference system conceived expressly for operation over active networks. The goal of this activity is to pinpoint the bene ts that mobile code and active networks bring in this application domain and to provide insights for the exploitation of these concepts in other application domains. 1

An active networking architecture provides the infrastructure for applications to inject user programs into the nodes of the network. This enables customization of the network nodes so that application-specific services can be downloaded into the network in the form of new protocols. In this paper

Traditional IP accounting infrastructures cannot withstand the shock waves produced by voice over IP integration, increasingly large accounting data volumes, adaptive pricing schema that reflect resource utilization, and real-time requirements on accounting applications such as billing and traffic monitoring. To suit tomorrow's networks, the Active IP Accounting Coprocessor Environment (AIACE) argues that the number of accounting tasks performed at the network nodes and at the accounting servers be fluid and not necessarily known a priori. The AIACE infrastructure introduces the notion of an active accounting co-processor coupled with the network node. This co-processor performs custom operations on accounting data exactly where the accounting data is being generated. For instance, the co-processor can efficiently manage pre-paid debit card semantics, reflect settlements among providers, apply fraud detectors, or enable real-time accounting data mining. The AIACE infrastructure dynam...