Application Bandwidth and Flow Rates from 3 Trillion Flows Across 45 Carrier Networks

Geographically broad, application-aware studies of large subscriber networks are rarely undertaken because of the challenges of accessing secured network premises, protecting subscriber privacy, and deploying scalable measurement devices. We present a study examining bandwidth consumption and the rate at which new flows are created in 45 cable, DSL, cellular and WiFi subscriber networks across 26 countries on six continents. Using deep packet inspection, we find that one or two applications can strongly influence the magnitude and duration of daily bandwidth peaks. We analyze bandwidth over 7 days to better understand the potential for network optimization using virtual network functions. We find that on average cellular and non-cellular networks operate at 61% and 57% of peak bandwidth respectively. Since most networks are over provisioned, there is considerable room for optimization. Our study of flow creation reveals that DNS is the top producer of new flows in 22 of the 45 networks (accounting for 20 – 61% of new flows in those networks). We find that peak flow rates (measured in thousands of flows per Gigabit) can vary by several orders of magnitude across applications. Networks whose application mix includes large proportions of DNS, PeerToPeer, and social networking traffic can expect to experience higher overall peak flow rates. Conversely, networks which are dominated by video can expect lower peak flow rates. We believe that these findings will prove valuable in understanding how traffic characteristics can impact the design, evaluation, and deployment of modern networking devices, including virtual network functions.