A Survey of Semantic Techniques for Active Networks

Active networks open up switches within the network to allow computation upon them. Because these switches are public resources, and are essential to the proper and correct running of many important systems, the safety and security requirements placed upon the computation environment must be much stricter than in many other environments. In this paper we describe the motivation for some basic system decisions and show how recent advances in the semantics of programming languages can meet the safety challenges presented by the system yet still provide good performance. As the corollary to this point, we argue that the construction of proofs over programs is a difficult thing to do, and should be left to the designer of the programming language and not the programmer. 1 What are active networks? Most networks currently have a topology where `smart' hosts sit at the edges of the network, and are connected by `dumb' switches: H H H H H R R R H R Active nodes Host Router Passive nodes In..