Throughput variance across Iranian ISPs collapsed nearly simultaneously during suspected throttling events, consistent with a centrally-coordinated administrative order rather than independent ISP-level decisions. Former ISP staff accounts cited in the paper indicate throttling orders were delivered by phone or fax, with smaller regional providers potentially delaying compliance—implying a brief window before universal enforcement.
From 2013-anderson-dimming — Dimming the Internet: Detecting Throttling as a Mechanism of Censorship in Iran
· §5.2, Fig. 8–9
· 2013
· University of Pennsylvania
Implications
Iran's centralized gateway architecture (all traffic routed through TCI/ITC AS12880) means a single throttling order can affect all users simultaneously; circumvention infrastructure should not rely on a single upstream path through the Iranian international gateway.
The compliance lag that smaller ISPs may exploit before throttling orders propagate suggests routing circumvention traffic through smaller regional ASNs could yield additional usable bandwidth during the initial hours of a suppression event.