Abstract

We present Tesseract, an experimental system that enables the direct control of a computer network that is under a single administrative domain. Tesseract’s design is based on the 4D architecture, which advocates the decomposition of the network control plane into decision, dissemination, discovery, and data planes. Tesseract provides two primary abstract services to enable direct control: the dissemination service that carries opaque control information from the network decision element to the nodes in the network, and the node configuration service which provides the interface for the decision element to command the nodes in the network to carry out the desired control policies. Tesseract is designed to enable easy innovation. The neighbor discovery, dissemination and node configuration services, which are agnostic to network control policies, are the only distributed functions implemented in the switch nodes. A variety of network control policies can be implemented outside of switch nodes without the need for introducing new distributed protocols. Tesseract also minimizes the need for manual node configurations to reduce human errors. We evaluate Tesseract’s responsiveness and robustness when applied to backbone and enterprise network topologies in the Emulab environment. We find that Tesseract is resilient to component failures. Its responsiveness for intra-domain routing control is sufficiently scalable to handle a thousand nodes. Moreover, we demonstrate Tesseract’s flexibility by showing its application in joint packet forwarding and policy based filtering for IP networks, and in link-cost driven Ethernet packet forwarding. 1

Citations