Correlation, visualization, and usability analysis of routing policy configurations

Network configurations implement a set of policies that control a network's behavior. Therefore, correct understanding of the configurations is vital to ensure that the network operates according to the intended policies. However, the current practice of manually reading a large number of configuration commands, which are written in low-level languages and distributed in multiple devices, is inefficient and significantly increases management costs and operator errors. We propose a system that helps decode network configurations by interpreting low-level fragmented configurations and then presenting their high-level intended policies. In particular, the proposed system is applicable to inter-domain routing policies, one of the most complex aspects of network configurations. We implement our system and evaluate its effectiveness through a set of user studies involving 44 participants. These studies examine the participants comprehension of routing policies presented with our system as compared to those presented with existing configuration languages. The studies show that our system improves both accuracy, from 70% to nearly 100%, as well as time-to-task-completion, from 30 minutes to 10 minutes. We believe that our system provides a basis for a clean separation of policy intent from its implementation so that policies can be better designed and understood. We also discuss the weaknesses in usability of current network configurations and argue that all aspects of future management systems need to be designed to address these usability issues.