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