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Cuba Up, Vietnam Down: Recent Subsea Cable Developments

Recent submarine cable-related developments have impacted internet connectivity in locales as diverse as Vietnam, Cuba, India, the Marshall Islands and Russia’s Kamchatka Peninsula.  In this blog post, we report on positive developments in Cuba and Russia and a few notable cable failures in other parts of the world.


The internet of Vietnam got off to a shaky start in 2017 when, on 8 January, the America-Asia Gateway (AAG) submarine cable experienced yet another of its many failures.  In September of last year, Tuoi Tre News reported that AAG had suffered its 10th failure in three years, prompting VietnamNet to ask the question: Why does the AAG underwater cable have to be repaired so often?  Over the years, we have frequently analyzed these cable breaks.  (For example, see this, this or this.)

Internet performance in Ho Chi Minh City suffers greatly during these unfortunate episodes.  For Saigontourist Cable Television (SCTV), the recent break meant a brief disruption in connectivity and the loss of NTT transit as illustrated below.

Following this year’s loss of AAG, the TGN-Intra Asia (IA) cable also suffered a failure, compounding the problems for Vietnamese internet connectivity.  Tuoi Tre News reported:

Intra Asia (IA) cable network was broken on Tuesday morning, compromising services provided by internet operators in Vietnam, especially Viettel.

The following graphic shows the impact of TGN-IA’s breakdown on military-run Viettel, as it failed in two distinct phases.

Here’s a view of the impact from Dyn’s Internet Intelligence, showing a spike in daily median latencies from Singapore to Ho Chi Minh City:

In recent discussions about the situation in Vietnam, submarine cable expert and good friend Julian Rawle recently told me:

Vietnam has four submarine connections.  The only one unaffected is SEA-ME-WE-3, the oldest and most capacity-constrained cable.  Vietnam presumably has terrestrial connections to Hong Kong via China in the North but this is probably an expensive option and adds to latency.  AAE-1 (RFS end 2017?) will alleviate the situation and there are rumors of another regional system being planned to connect Vietnam to Singapore.  Vietnam is living proof that you can never have enough redundancy!


While Vietnam struggles through its latest bout of submarine cable issues, the internet of Cuba continues to make incremental steps towards improved international connectivity.  In October, we tweeted that Cuba’s state telecom ETECSA had gained its first new transit provider, Curaçao-based UTS, since we broke the news that the ALBA-1 submarine cable had been activated in 2013.

In December, Google announced that it had reached a deal with ETECSA to host Google Global Cache servers inside Cuba.  The primary benefit of GGC servers is caching traffic-intensive Youtube videos – and the benefit can be tremendous.  Instead of pulling a popular video over the ALBA-1 submarine cable say 1,000 times in a day, it can be pulled once, cached, then quickly delivered from GGC servers inside ETECSA another 999 times.

While the primary challenge to improving the internet in Cuba remains expanding the access layer so that more people can directly connect via fixed line and mobile services, local hosting of content is also an important step in the development of this island nation’s internet.  (Note: As of this writing, we haven’t yet detected evidence that those GGC servers are active, but it is reasonable to expect them to come online any day.)

More recently, we observed ETECSA gain a new transit provider, C&W Networks, formerly Columbus Networks.  The addition of C&W Networks marks the first time a U.S. telecommunications firm (C&W Networks is owned by Liberty Global) has provided direct transit to Cuba’s state telecom ETECSA.  It is also perhaps the first time a U.S. telecommunications firm has directly provided internet service into Cuba since my friend Jesus Martinez established the first Cuban internet connection to the outside world in 1996 using a satellite link from Sprint.  (See write-up by Larry Press here).

At any rate, here’s how we see Cuban BGP routes being transited over the past week.  C&W Networks and ETECSA first established a BGP adjacency at exactly 16:28:17 UTC (11:28:17am local) on 10 January 2017 and the use of this new connection has been steadily increasing as more Cuban networks are routed through C&W Networks (in green below).

Another item to note with this new transit service to Cuba is that it is being served from Boca Raton, Florida and reaches Havana in 35ms round-trip, making it the lowest-latency link to the United States.  See the following example traceroute.

We suspect that C&W Networks may be reaching Cuba using their Colombia-Florida Subsea Fiber (CFX-1) cable to reach Jamaica before cross-connecting to ALBA-1‘s backup leg that also lands in Jamaica.  The Jamaica leg of ALBA-1 was also briefly activated in 2013.


colombia_florida_subsea_fiber alba_1


Images above are courtesy of by our good friends at Telegeography.

Other recent submarine cable events

As new submarine cable systems continue to come online (SeaMeWe-5 and AAE-1 being the latest major projects), the internet continues to become more resilient and less susceptible to widespread impairment due to the inevitable submarine cable cut.  The last such catastrophic incident was perhaps the sabotage of SeaMeWe-4 in 2013.

Nevertheless, cable failures (and activations!) still happen with some regularity.  Here’s a quick recap of some other interesting submarine cable developments in recent months.


On 12 December, Cyclone Vardah damaged the i2i submarine cable causing performance problems for traffic traversing Chennai, India.  Below is a visualization from Dyn’s Internet Intelligence showing the impact on latencies from Singapore to Chennai as a result of this cable break.

Marshall Islands

The submarine cable serving the Marshall Islands in the Pacific Ocean suffered a cut on 28 December 2016. The national telecom shifted transit to satellite and blocked the streaming of movies and video to conserve bandwidth.  The full timeline of the submarine cable outage and subsequent restoration is depicted in the graphic below.

Kamchatka Peninsula

And finally to end on a high note — a submarine cable activation!  The Kamchatka Peninsula is a remote and thinly-populated region in the Russian Far East.  Until recently this region received its internet service through a high-latency satellite link.

Last year, Russian state telecom Rostelecom contracted with Huawei Marine to build a new submarine cable to improve connectivity in this region.

In September, Huawei Marine announced the cable’s completion and, in October 2016, we saw it flicker to life.  The local Russian ISP announced Быстрый Интернет уже у нас!  (“Fast Internet is finally here!”)  The activation of this cable is depicted below.


In an analysis such as this, one that spans geography, it is interesting to reflect on the human endeavor that is the global internet, namely, engineers in all corners of the globe actively working to better connect humanity.  It is a privilege to be in the position we’re in — documenting on this blog the interesting developments in this endeavor as it unfolds and we look forward to continuing to do so into the future.

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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.

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