Routing fountains: leveraging broadcast channels to improve the dissemination of control information for large inter-domain networks

The utility of a large inter-domain network depends on neighboring networks exchanging routing control information and using that information to compute next-hop forwarding decisions. While this approach of hop-by-hop information dissemination has proven very useful for the incremental expansion of the Internet, it is limited in providing the necessary performance to accommodate for future network growth, mobility, and security. ❧ To address these challenges, we present a novel architecture that leverages broadcast channels for disseminating routing information. The key components of our architecture are devices called `Routing Fountains' that perform the task of collecting routing information from each of the participant networks and then simultaneously redistributing this information back to the greater set of networks through a wide area broadcast channel, like a satellite downlink. By complementing existing routing infrastructures with Routing Fountains, we augment the route distribution graph in a way that: 1.) Drastically reduces the number of transmissions needed to communicate routing updates, 2.) Provides synchronization to the route distribution process, and 3.) Facilitates the validation of routing data. Our architecture is designed to augment and therefore coexist with current routing infrastructures so that incremental performance gains can be achieved without disruption to existing infrastructures. ❧ Utilizing a broadcast based architecture provides compelling opportunities to improve the performance of today's inter-domain routing architectures. To demonstrate the utility of this approach we have applied it to the following three inter-domain routing tasks: 1.) Distributing routing updates across the entire Internet topology, 2.) Facilitating minimal loss network transitions for mobile networks while maintaining shortest path connectivity, and 3.) Protecting against the distribution of fictitious routing information. The results from our Internet graph and routing traffic analysis, simulations, and testbed prototypes demonstrate that utilizing broadcast channels has remarkable value in improving the performance and robustness of existing route distribution infrastructures, even when only a subset of the larger network is actively receiving the broadcasted information.