Russia has tested its high-speed military internet that can send encrypted data over long distances, the pro-Kremlin Izvestia newspaper reported Thursday.

The secure military internet tests come three months before parts of a Russian law tightening state control over the internet come into effect. Lawmakers say “internet sovereignty” will protect the Russian-language segment of the internet in case it is disconnected from the World Wide Web, while critics argue that the law is vague and unenforceable.

Encrypted signals, including large audio and video files, were sent across more than 2,000 kilometers over dedicated radio channels at a speed of 300 megabits per second, Izvestia cited Russia’s Defense Ministry as saying.

“Unlike the internet, these are completely closed-off channels,” said Viktor Murakhovsky, an expert at Russia’s Military Industrial Commission.

“The main advantage of military communication networks is that they’re completely autonomous and resistant to external influence. They can’t be accessed by third-party consumers even theoretically,” Murakhovsky said.

The tests reportedly involved more than 1,500 mobile communication and encryption packages, digital video conferencing systems and space communication stations. More than 4,500 Russian Central Military District troops deployed the equipment within an hour, Izvestia reported.

The news comes a month after Germany and the Netherlands signed a joint military internet deal to share defense communication networks.