Introduction
According to http://phys.org/news/2013-01-cuba-fiber-optic-link-venezuela.html a 1,600-kilometer (994-mile) cable between Venezuela and Cuba, estimated to cost $70 million, was actually completed in February 2011 and was due to come into operation in July 2011. It was switched on in January 2013.
In its statement, Etecsa said the cable has been "operational since August 2012," and was initially tested with international telephone traffic.
But it warned that the "conclusion of the testing process ... will not automatically mean an increase in access" for Cubans to the Internet.
"It will be necessary to make investments in the domestic telecommunications infrastructure and increase foreign exchange resources to pay for Internet traffic in order to achieve the gradual growth of a service we provide mostly for free today," Etecsa said.
According to http://cuba.blogspot.com/2013/05/cubas-fibre-optic-link-to-venezuela.html 5/29/2014
The government is creating an additional 118 outlets, which will make
use of faster bandwidth thanks to undersea fibre optic cables between
the Caribbean island to Venezuela. Cuba cannot use others due to a US
embargo.
Starting from June 4, the extra access will be provided by the state
telecommunications monopoly ETECSA for a reduced price than is currently
charged.
However, there still be no internet provided directly to private homes.Cuba has one of the lowest rates of internet usage in Latin America.
There are only 2.6 million users out of a population of 11.1 million.
Given the various dates above we decided to use the PingER data of measurements to Cuba to see when the minimum Round Trip Time (min-RTT) dramatically reduced from the > 450ms of a typical geostationary link to a shorter min-RTT associated with a terrestrial link (such as provided by the undersea fibre optic cable between Venezuela and Cuba.
Change in RTT
The plot below shows the minimum RTTs measured from SLAC to a host in Cuba. It is seen that the change occurred in Jan 2013. (spreadsheet)
More details are shown in the plot below that This plot below shows that the change from Satlink to terrestrial took place in a few steps. First on 14th Jan, one way route was changed to terrestial.
...
It appears this host has much lower losses and jitter than the www.egrem.com.cu host seen below for thye saem same time period
Looking back at the beginning of 2014 it can be seen that until about May 16, 2014 the performance to www.uclv.edu.cu was dreadful even though minimum RTTs were aroung 160ms.
Routing
The route from SLAC to www.uclv.edu.cu goes via ESnet to Sunnyvale back to Palo Alto where it enters the Tata communication network goes to Chicago and thence to Montreal