Active Reliable Multicast on CANEs: A Case Study

This paper presents a case study in implementing a moderately complex, useful service on an active network platform. The active application is reliable multicast with congestion control; the platform comprises the Bowman Node Operating System and the Composable Active Network Elements (CANEs) Execution Environment. The importance of the work stems from the lessons it provides about the design and implementation of active platforms in general and Bowman/CANEs in particular. For example, our experience shows that timer-driven active node processing is as important as packet-arrival-driven processing. Thus, execution environments cannot focus exclusively on forwarding, but must also provide efficient timers and allow timer handlers the same capabilities as packet-driven computations. Other areas in which the implementation provides insight include service decomposition approaches for active applications and information sharing among service components.