Résumé: Virtual active networks (VANs) are dynamically constructed virtual networks of packet processing nodes and QoS-enabled tunnels that support application-specific services, such as Web caching, multi-casting, transcoding, and filtering, etc. The goals of a VAN are to enable large-scale multi-edged network applications, i.e., applications with components distributed at network edge nodes, to control and configure network topology and resources to best support their needs; and to enable these applications to monitor and adapt to network changes. In this paper, we describe the VAN architecture, a middleware that provides services and mechanisms to achieve these goals. In particular, the VAN architecture provides: (1) abstractions for applications to specify a VAN; algorithm to map the VAN specification to physical network topology and resources; and protocols to acquire the topology and resources. (2) Algorithm and protocol to resolve deadlock among competing VANs for shared node and link resources. (3) Mechanisms to recover from physical network failure in order to preserve VAN service properties.

Langue: Anglais