Dimming the Internet: Detecting Throttling as a Mechanism of Censorship in Iran

TL;DR

This paper investigates how governments, particularly Iran, use Internet throttling to censor content by degrading connection speeds, and proposes a measurement-based approach to detect and monitor such practices for accountability.

Contribution

It introduces a methodology for detecting Internet throttling as a censorship mechanism using network measurements and applies it to analyze Iran's recent Internet restrictions.

Findings

Evidence of widespread Internet throttling in Iran post-2009 election

Throttling used to degrade multimedia content access

Potential for monitoring systems to increase transparency

Abstract

In the days immediately following the contested June 2009 Presidential election, Iranians attempting to reach news content and social media platforms were subject to unprecedented levels of the degradation, blocking and jamming of communications channels. Rather than shut down networks, which would draw attention and controversy, the government was rumored to have slowed connection speeds to rates that would render the Internet nearly unusable, especially for the consumption and distribution of multimedia content. Since, political upheavals elsewhere have been associated with headlines such as "High usage slows down Internet in Bahrain" and "Syrian Internet slows during Friday protests once again," with further rumors linking poor connectivity with political instability in Myanmar and Tibet. For governments threatened by public expression, the throttling of Internet connectivity appears to be an increasingly preferred and less detectable method of stifling the free flow of information. In order to assess this perceived trend and begin to create systems of accountability and transparency on such practices, we attempt to outline an initial strategy for utilizing a ubiquitious set of network measurements as a monitoring service, then apply such methodology to shed light on the recent history of censorship in Iran.