OPERA: An open-source extensible router architecture for adding new network services and protocols

In this paper, we present the design and implementation of a programmable and extensible router architecture. The proposed architecture not only provides the conventional packet forward/routing functions, but also the flexibility to integrate additional services (or extension) into a router. These extensions are dynamically loadable modules so one can easily deploy new services, such as reliability and security enhancement, onto the router in a dynamic and incremental fashion. To avoid new extensions that may monopolize system resource and degrade the performance of normal packet forwarding/routing function, we propose a novel CPU resource reservation scheme which facilitates the efficient use of resources and increases the stability of extension execution. To illustrate the “extensibility” and “effectiveness” of the proposed architecture, we present the results of a new service, namely, how to perform “Distributed Denial-of-Service (DDoS) attack traceback”. In particular, we illustrate the deployment of the probabilistic marking in performing IP traceback. Note that this approach requires the collaboration of routers so that effective traceback can be performed. Currently, the programmable router platform is released as an open source1 and we believe the system provides an ideal platform for researchers to experiment and to validate new services and protocols.