Date Added: Nov 2011
Better exposing congestion can improve traffic management in the wide-area, at peering points, among residential broadband connections, and in the data center. TCP's network utilization and efficiency depends on congestion information, while recent research proposes economic and policy models based on congestion. Such motivations have driven widespread support of Explicit Congestion Notification (ECN) in modern operating systems. The authors reappraise the Internet's ECN readiness, updating and extending previous measurements. Across large and diverse server populations, they find a three-fold increase in ECN support over prior studies. Using new methods, they characterize ECN within mobile infrastructure and at the client-side, populations previously unmeasured.