Design for Network Managability Mung Chiang and Jennifer Rexford Princeton University March 2007

Making Networks Easier to Manage The boundary between network elements … and the systems that manage them Managing IP networks is inherently hard –Not designed with management in mind –Induces difficult-to-solve management problems –Leading to expensive, convoluted solutions Design for manage-ability –New architectures that are easier to manage –Easier to control, and easier to measure

Managing a Network Network Network-wide objectives optimization tomography measurement (dials) control (knobs)

Our Goals and Approach Our philosophy –Change the system to make it easier to manage Our goal: understand fundamental trade-offs –Optimization: optimality vs. complexity –Tomography: accuracy vs. overhead –To advocate judicious changes to the network Our approach –Analyze limitations of the existing system –Explore two case studies on each topic –Identify principles for design for manage-ability

Design for Optimizability Optimization: control –Configuring tunable parameters to optimize –E.g., traffic engineering within a single domain –E.g., selecting egress point in interdomain routing –Challenge: optimal solutions infeasible/intractable Today: TE within a single domain –Optimal traffic engineering with link-state routing –Online traffic management in future networks –Goal: understand optimality vs. complexity –Talks by Dahai Xu and Jiayue He

Design for Tomography Tomography: measurement –Inferring properties from the measurement data –E.g., detect and localize path-quality problems –E.g., traffic matrix from link-load statistics –Challenge: highly under-constrained problem Today: infer path quality despite adversaries –Passive sampling rather than active probing –Accounting for adversaries in the network –Goal: understand accuracy vs. overhead trade-off –Talks by Yannis Avramopoulos & Sharon Goldberg

Design for Network Manageability (Seedling) DESCRIPTION / OBJECTIVES / METHODS Reveal dimensions in which network management is a technical challenge rather than simply programming Perform trade-off studies concerning network management design dimensions Discover design principles for network manageability –Two case studies on tomography (input to network management): identify architectural elements that induce simpler network inference problems –Two case studies on control (output from network management): identify architectural elements that induce simpler control problems MILITARY IMPACT Total budget: $250k Case Study 1Q072Q073Q07 Link inference Traffic matrix estimation Inter-AS routing Egress point selection J. Christopher Ramming, STO Technical foundations for future network management software initiatives Reduced network-management costs – Easier configuration & troubleshooting – Fewer man hours & simpler software Fewer network outages – Faster network troubleshooting Improved network efficiency – Protocols with smaller optimality gap – Protocols that are easier to tune – Measurements that match the tasks SCHEDULE AND BUDGET (9 month Seedling) Hard tomography and control problems Ad hoc network management Existing protocols and monitoring Network Management Tractable tomography and control problems Well-defined management tasks New and improved protocols & monitoring Design for Manageability