Unmasking the Growing UDP Traffic in a Campus Network

Transmission control protocol (TCP) has been the dominating protocol for Internet traffic for the past decades. Most network research based on traffic analysis (e.g., router buffer sizing and traffic classification) has been conducted assuming the dominance of TCP over other protocols. However, a few recent traffic statistics are showing a sign of significant UDP traffic growth at various points of Internet links [21]. In this paper we show that the UDP traffic has grown significantly in recent years on our campus network; we have observed a 46fold increase in volume (from 0.47% to 22.0% of total bytes) in the past four years. The trace collected in 2011 shows that the grown volume is not from a small number of UDP hosts nor port numbers. In addition, the recent UDP flows are not sent at constant bit rate (CBR) for most cases, and the aggregated traffic shows burstiness close to TCP traffic.