The effects of Active Queue Management and Explicit Congestion Notification on DNS traffic

Active Queue Management (AQM) and Explicit Congestion Notification (ECN) are two methods that attempt to alleviate the problems of FIFO queues and of packet drops for congestion indication respectively. Random Early Detection (RED) is the most popular AQM method. The Domain Naming System (DNS) protocol is a core Internet protocol with very high impact on user experience and overall network functionality. This paper presents experimental results that show an inefficiency of RED that results in degraded performance of the DNS protocol when compared with FIFO queues. The results that are presented show 8 to 50 percentage points drop of DNS efficiency depending on network conditions.