New models and algorithms for programmable networks

In today's IP networks most of the network control and management tasks are performed at the end points. As a result, many important network functions cannot be optimized due to lack of sufficient support from the network. The growing need for quality guaranteed services brought on suggestions to add more computational power to the network elements. This paper studies the algorithmic power of networks whose routers are capable of performing complex tasks. It presents a new model that captures the hop-by-hop datagram forwarding mechanism deployed in today's IP networks, as well as the ability to perform complex computations in network elements as proposed in the active networks paradigm. Using our framework, we present and analyze distributed algorithms for basic problems that arise in the control and management of IP networks. These problems include: route discovery, message dissemination, topology discovery, and bottleneck detection. Our results prove that, although adding computation power to the routers increases the message delay, it shortens the completion time for many tasks. The suggested model can be used to evaluate the contribution of added features to a router, and allows the formal comparison of different proposed architectures.