Kentucky was only ever going to be a summer job. Come fall, Blue Riley would be back in North Carolina, in college. But one job led to another, one town led to another, and one woman led to another. Now, after twenty years Blue faces the hardest question of all—is it time to go home?

This book constitutes the refereed proceedings of the 12th International Conference on Passive and Active Measurement, PAM 2011, held in Atlanta, GA, USA, in March 2011. The 24 revised full papers presented were carefully reviewed and selected from 56 submissions. The papers were arranged into seven sessions covering passive measurement, wireless models, bandwidth, automated bots, route avoidance, interdomain protocols, timing, and diagnosis.