A Case for Complexity Models in Network Design and Management

Anecdotal evidence and intuition suggest that an operator’s ability to manage a network decreases as the network becomes more complex. However, there is currently no way to systematically quantify how complex a network’s design is nor how complexity may impact network management activities. In this paper, we develop a suite of complexity models that describe the routing design and configuration of a network in a succinct fashion, abstracting away details of the underlying configuration languages. Our models, and the complexity metrics arising from them, capture the difficulty of configuring specific control and data plane behaviors in various routers. They also enable measurement of the inherent complexity of reachability constraints that a network implements via its routing design. Our models simplify network design and management by facil- itating comparison between alternative designs for a network. To demonstrate their value, we use the metrics to perform a comparative study of the complexity of five different networks, including three university networks and two enterprise networks.

Download this report (PDF)

Return to tech report index