Blue Coat takes a WAN for a Moon walk

To commemorate the 40^th anniversary of the first moon landing on July 20, Blue Coat set up a WAN optimisation deployment that simulated accessing a computer file between Earth and the Moon.

The average distance from the moon to the Earth is 384,403 kilometres, and a computer session between the two would comprise the longest Wide Area Network (WAN) connection in the solar system.

In tests run by Blue Coat Systems, a 2.5 megabyte file from a location on earth required 5 minutes and 12 seconds (312 seconds) to download on the moon.

With a Blue Coat ProxySG appliance for WAN optimisation, the same file could be downloaded in as little as 11 seconds, a 96 percent reduction in time required to transmit a file.

"We ran the tests in our lab using a client PC, server and a WAN simulator between them to create conditions similar to how they would act in a production environment," Steve Schick, senior director, corporate communications at Blue Coat Systems, said.

"In particular, the WAN simulator introduces latency to the connection between the client and the server. Latency is the amount of time it takes for a network packet to travel between points. Latency is bounded by the speed of light (it's impossible to travel faster than the speed of light).

"Given the distance between the moon and earth and the speed at which light travels, we were able to very closely approximate the latency."

Schick said this latency "handicap" was used to conduct the tests to show how much time it would take a packet to travel between the earth and moon.

"A packet is the smallest unit of information that traverses a network or computer connection," he said.

"It takes a great many packets to transmit a large file across a network.

"Each packet transference was then subject to the latency or time for a roundtrip between the points. For a large file, many, many roundtrips are required to download it from a server to a client computer."

He said compression was once the primary remedy for network data transmission between the distant point on earth.

"As more files, data and applications became centralised and as more employees were staffed in branch offices, companies began to experience very slow response times in accessing data or getting an application to respond," he said.

Schick said as more space missions will need to access data and applications on earth, WAN optimisation techniques must be applied, and they are likely to result in dramatic increases in speed for accessing them.