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Faraway Fallout from Black Sea Cut



Last month,‘s fascinating geological sciences blog, Eruptions, cast doubt on the purported cause of the December 23, 2012 failure of the Georgia-Russia submarine cable. That is, the author of the Eruptions blog post thought it unlikely to have been due to an undersea volcanic eruption. Without weighing in on the likelihood of active volcanoes in the Black Sea, we tweeted about some of the Internet impacts of this incident, although in 140 characters, we could only scratch the surface.We’ll take a more in-depth look in this blog, noting shifts in traffic as far away as Oman, more than 3,000 kilometers distant!blacksea_cables.png

Fiber Cuts in the Caucasus

But first, let’s consider some recent history. The last time a fiber optic cable cut in the Caucasus grabbed international attention was almost two years ago (March 28, 2011) when a 75 year old Georgian woman reportedly severed the major terrestrial fiber optic cable serving the region while collecting scrap metal.After her arrest, she told the press she had never heard of “the Internet” and that she did not break the cable, which knocked out western Internet transit for providers in Georgia and Armenia at exactly 13:00 UTC. I emphasize western because Russian incumbent, Rostelecom, was still serving the region from Baku, Azerbaijan during the fiber outage. Headlines suggesting Armenia was completely offline were incorrect, the cut just shifted the remaining Georgian and Armenian traffic through Rostelecom until the fiber was fixed less than 8 hours later at 20:32 UTC. 258446-hayastan-shakarian.jpg

Although Armenian incumbent Armentel was entirely dependent on the severed cable, other Internet providers in Armenia such as Fibernet, which had Russian transit, were able to survive the incident relatively unscathed. In the graphics below, we observe traceroute measurements into both Armentel (AS 12297) and Fibernet (AS 41965) on March 28, 2011.

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In upper left, Armentel’s service from global provider TeliaSonera and Armentel’s parent company, Russian provider Vimpelcom, were lost during the incident. In the upper right, Fibernet lost Level 3 service from the West, but not Internet transit from Rostelecom.

As a result of this incident, we saw an uptick in western and Russian transit diversity in the region as presented by my colleague Jim Cowie in June 2011 at the Eurasia Network Operators Group conference in Moscow.

Impacts of the Georgia-Russia cable cut

After this fiber cut and repair in 2011, Internet access to the region was relatively stable until recently. As we tweeted last month, service into Georgia from Azeri provider Delta and service in Armenia via Armentel were impacted by the Black Sea submarine fiber cut. Armentel lost its service from parent company, Vimpelcom, initially replacing it with transit through Caucasus Online and later TeliaSonera. Delta lost its primary transit provider for Georgia, Russian provider TransTelecom (TTK) (AS 20485), and made up for the loss with additional transit from Tata (AS 6453) and Level 3 (AS 3356) to the west and Rostelecom to the east.

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On Tuesday of this week, headlines in Armenia carried the news that Armentel had just days prior expanded their international bandwidth capacity by again acquiring service from TeliaSonera. Prior to the headlines, users of Renesys’s Market Intelligence had spotted the change in service in its news feed.


Impacts on Iranian Transit

Providers in Georgia and Armenia were not the only ones to lose Russian transit when the Georgia-Russia cable failed. Iran also uses Russian transit to access the Internet, some of which was dependent on that cable. On January 7, Iranian news carried a story (cached English translation) with the headline “Internet slow over the last week due to an earthquake reported in Georgia”.

Iranian incumbent TIC, previously known as DCI, uses two ASNs for its International gateways, AS 12880 and since last year, AS 48159. As can be seen from the transit shift graphics below, the fiber break had no impact on upstreams of AS 12880. However, AS 48159 lost its service from Rostelecom when the cable was cut. What is more interesting is that the loss of Rostelecom for AS 48159 appears to have immediately triggered the activation of a dormant backup transit link from Omantel. This is the first time we have seen Omantel providing Internet service in Iran (although we did observe Omantel and TIC testing this connection from November 3 to 7, 2012). For good measure, TIC also added Delta as a provider in early January for both of its ASNs — representing another completely new business relationship. Of course, all of these changes were also identified in Market Intelligence.

12880_IR_blacksea.png 48159_IR_blacksea.png
The activation of this connection could be evidence that the final leg of the Europe-Persia Express Gateway (EPEG) fiber optic cable connecting Iran to Oman has been completed. It was this segment of the cable system that was blamed for the delay of the launch of EPEG last year. Two weeks ago, Azeri press announced EPEG would be activated this month. If activated, EPEG could serve as a vital terrestrial alternative to the dozen or so submarine fiber optic cables through the Suez canal which connect Europe and Asia — thereby mitigating this potential single point of failure for global communications. epeg.png

So was it an undersea Volcano?

The most likely cause of the cable break in the Black Sea was the magnitude 5.7 earthquake, which struck a little more than an hour before traffic stopped flowing and appears to have occurred under the path of the cable. Regardless of the cause, it is fascinating to see how an earthquake in the Black Sea can immediately impact Internet pathways as far away as Oman. The Black Sea and the Caucasus are the Internet crossroads where Russian, Turkish, Gulf State, and Central Asian traffic mingle on their way to the datacenters of Western Europe and the Americas. Small impacts to particular cables can have large impacts on the flow of traffic regionally. Such is the Internet and our increasingly interconnected world. If you want to learn more from the operators involved, come join us at MENOG 12 (March 6, Dubai) and ENOG 5 (May 27-28, St Petersburg). exposure.png

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Doug Madory
Whois: Doug Madory

Doug Madory is a Director of Internet Analysis at Oracle Dyn where he works on Internet infrastructure analysis projects. Doug has a special interest in mapping the logical Internet to the physical lines that connect it together, with a focus on submarine cables.