Iran’s government might not have completely cut off Internet access within its borders, as have other governments suffering from political unrest. However, new evidence shows that the Data Communication Company of Iran (DCI) has been manipulating the overall flow of traffic to the country, according to Craig Labovitz, chief scientist for Arbor Networks, a company based in Chelmsford, MA, that provides network security and analysis for many Internet service providers and large businesses.

Although Labovitz has no information directly from Iran, he has based his conclusions about Iranian traffic on data collected from more than 100 Internet service providers that together allow Arbor Networks to form a picture of global Web traffic.

Labovitz found that on June 13, the day after elections, Iranian traffic fell off almost completely. Traffic came back a few hours later, he writes, though just a little. By June 16, Labovitz says, it was back to about 70 percent of normal.

Labovitz writes,

So what is happening to Iranian traffic?

I can only speculate. But DCI’s Internet changes suggest piecemeal migration of traffic flows. Typically off the shelf / inexpensive Internet proxy and filtering appliances can support 1 Gbps or lower. If DCI needed to support higher throughput (say, all Iranian Internet traffic), then redirecting subsets of traffic as the filtering infrastructure comes online would make sense.

Unlike Burma, Iran has significant commercial and technological relationships with the rest of the world. In other words, the government cannot turn off the Internet without impacting business and perhaps generating further social unrest. In all, this represents a delicate balance for the Iranian government and a test case for the Internet to impact democratic change.