Active networks: Applications, security, safety, and architectures

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 problem is defined, and techniques for solving it are presented and elaborated upon with a description of a specific implementation of a secure environment and related performance measures. Issues related to the design of a programming language for active networks are also discussed. The third goal is to classify active network architectures based on their design approach. Thus an inclusive presentation of currently proposed architectures, which focuses on their design attributes, capabilities, performance, and security, is given.