But it has cracked down further in recent weeks, targeting virtual private networks (VPN), used by many people to get access to material overseas.
Documents show that Edgehill's initial aim was to decode the encrypted traffic certified by three major (unnamed) internet companies and 30 types of Virtual Private Network (VPN) – used by businesses to provide secure remote access to their systems.
Iranians accessing a filtered website without using a VPN used to be confronted with a message notifying them that the site had been filtered for "criminal" content.
If it does not, I'd take it as proof for the argument that the government does not want VPN use to spread because while DNS circumvention allows for YouTube access, it does not allow for Twitter access where most of the political link distribution takes place.
I already wrote an article explaining VPNs using simple concepts, even comparing VPNs to movie car chases.
Web users also said internet speed has improved, with the restoration of access to VPNs used to bypass filtering and less jamming of satellite signals by the state.
Some users of their own companies' VPNs, used for secure communications within corporate networks, report similar problems, says Duncan Clark of BDA China, a consultancy in Beijing.
VPNs use IPSec, PPTR, or L2TP as the tunneling protocol.
VPNs use secure tunnels to allow remote users to connect to a network.
