Let me back up for a moment and review what's visible today, and how we interpret it. Renesys collects independent routing table perspectives from Internet service providers all over the world, and fuses them to get a daily picture of the evolving economic relationships (provider-customer, peer-to-peer) that allow Internet traffic to flow. Our Market Intelligence product uses this evolving roadmap to give Internet transit wholesalers critical visibility into the commercial relationships in the markets where they make their money.
As you might guess, when we look at this aggregate global routing table, we learn a lot about the size and structure of the Internet transit marketplace in a particular region. In this case, as we observed back in June, it's clear that Iran has a very rich internal Internet, with dozens of service providers and content providers. It's one of the oldest and most advanced domestic Internet ecosystems in the region, with a very sizable and sophisticated domestic audience.
However, nearly all of Iran's international traffic (packets bound for Twitter, Google Mail, Yahoo, etc.) must squeeze painfully through a state-imposed bottleneck. One organization, DCI (Data Communications Iran), the Internet arm of the state telecommunications company, serves as a common transit gateway. This gives the Iranian government a centralized locus of control from which to monitor and filter international Internet traffic.
Getting Out of Iran
So, the obvious question: where does the Iranian government purchase its international Internet transit? Think for a moment about the constraints that they have to satisfy. They need enough capacity to sustain a 21st century information economy. They want to maintain centralized control over all that information. They have the challenge of maintaining adequate logical and physical diversity, so that a single point of failure can't take down the whole country's Internet access (unless they choose to do so themselves!). And they have the additional headache of choosing providers that are geopolitically diverse, to route around sanctions and military threats.
Take a look at the map of Iran and its neighbors. The good choices are few and far between. In the south, they can access the UAE over a submarine fiberoptic link from Jask to Fujairah, built by Alcatel-Lucent. This is the obvious way out, as it gives access to the primary submarine fiber paths headed east (to Asia) and west (to Europe). You get your choice of service providers once you reach the Emirates, and Iran has historically made good use of this diversity. But in the end, it's logical diversity, not physical diversity. A thin piece of glass strung across one of the world's busiest and tensest energy shipping lanes is not what you want to hang the nation's Internet future on.
So they established a connection to Turkey along a terrestrial fiber route to the northwest, from Tabriz to the frontier and on to Ankara and Istanbul along the gas pipeline. Turkey is an important regional conduit for Internet transit to Europe, and the Turkish government has quietly signalled their support for Iran's right to nuclear self-determination in recent months, as part of a warming relationship. Still, one can imagine that the Iranian government might want to seek a third way out, to further improve their diversity in times of political crisis.
Where else can Iran turn for transit?
The southeastern frontier goes to Pakistan through divided Baluchistan; this would be a fine path to reach Asian transit, but would be politically complicated. The TAE cable system also goes to Turkmenistan along the northeastern frontier, but it's unlikely to offer the kind of capacity or stability that you'd want for a primary backup route. Afghanistan and Iraq are out, for obvious reasons. Armenia will be an interesting choice someday, when the railroad goes in, but lacks the capacity today.
That leaves the Caspian coastal route to Azerbaijan, following existing pipelines to Baku. We've seen DCI use the Azeri route before, showing brief evidence of limited transit through Azerbaijan's Delta Telecom in 2008-2009. Baku has been a nexus for gas and oil transport for many, many years: north through Russia, south through Iran, west through Georgia. The Internet follows these same routes, with copper and glass fiber laid alongside existing rail and pipeline resources. And indeed, this is the route that Iran seems to have chosen to complete their Internet diversity play in the weeks leading up to the commemoration of the 1979 Revolution.
Enter the Russians
Two weeks ago, on January 26th, Russia's Rostelecom suddenly stepped in as another major transit provider to DCI, visible in the global Internet routing tables. This plot shows the relative stability of DCI's transit relationships over the preceding 16 months. Each international transit provider's percentage of Iran's transit is rendered in a different color; they all add up to 100% each day, but the mixture changes over time. DCI seems to change its provider mix just before significant events: TeliaSonera (brown) joins the provider mix in the weeks before last year's election. Rostelecom (yellow) shows up two weeks before the commemoration of the Revolution.
If we zoom into the last four months, we can see how abruptly DCI's transit preferences have shifted. Rostelecom has suddenly and decisively become the third-most important provider for Iran's international transit, behind Turk Telekom (TTnet) and TeliaSonera.
For Iran, it's a smart choice in two ways.
First, buying Russian transit actually makes good technical sense. Rostelecom and other Russian providers have made huge progress building out their domestic networks and their connectivity to European and Asian markets. Their terrestrial east-west capacity is ample, diverse, and poses an increasingly attractive alternative to the southern submarine cables. Would you rather wait two weeks for a fix to a cable on the ocean floor, or a few hours for a fix to a fiber along a rail line?
Secondly, of course, from Iran's perspective, Russian transit makes for great geopolitical diversity. In the last year, Iran and Russia have made a lot of visible progress on strategic military and energy coordination. The appearance of northbound Internet transit provides additional evidence that beyond the tactical concerns of censoring its citizens' access to Western Internet content, the Iranian government is thinking strategically about cyberspace as a national resource to be defended.