Detecting Middlebox Interference on Applications

Middleboxes are widely used in today’s Internet, especially for security and performance. Recent studies have uncovered and studied middleboxes in different types of networks. Middleboxes classify, filter and shape traffic, therefore interfering with application performance. In this paper, we propose a tool to detect and locate middlebox interference for specific applications, specifically DNS and HTTP. The tool sends probes with crafted IP TTL and application payloads from multiple vantage points, that provides the ability to identify any middlebox interference in both directions of the traffic flows. In addition, we capture and analyse all transmitted packets to figure out the hop range of middlebox location.