Facebook has joined a consortium that will build by far the fastest intra-Asia submarine fiber optic network, the Asia Pacific Gateway (APG). Facebook is the only American company involved with the venture, which will see 10,000km (6,000 miles) of prime fiber laid between Malaysia and Japan (pictured above), with branches landing in almost every country along the way (Singapore, Thailand, Vietnam, China, Taiwan, and South Korea).

When the cable goes online in 2014, it is slated to use 40Gbps channels, for a total capacity of 55 terabits per second, or a transfer speed of 6.9 terabytes (138 Blu-ray discs) per second. When the various routers and repeaters are upgraded to 100Gbps-per-channel, the cable will have a total capacity of well over 100Tbps. The members of the consortium have put forward a total of $450 million so far, which makes it one of the most expensive submarine cable systems in the world.

The prime reason for building the cable, other than making money, is to provide more redundancy between the US and Asia. Currently, almost every connection from Asia to the US is routed through Singapore or Japan. If there is congestion at one of these sites, or a cable is cut, then the other (highly populous) countries in south east Asia are in trouble. It is perhaps no surprise that China Telecom and China Unicom, two of the world’s largest telecoms companies, are involved in the laying of APG. Time dotCom, another member of the APG consortium, says that the new cable will reduce latency between the US and Asia — which is fairly important, considering how many internet services are based in the US.

Beyond redundancy, this cable (and Facebook’s involvement) is significant for one very important reason: Over the next few years, almost all of the internet’s growth will occur in Asia. The total number of internet users has almost stagnated in Europe and North America — while in China, India, and south east Asia, hundreds of millions of people are connecting to the internet every year. Facebook has almost reached saturation point in Europe and North America, while its growth in Asia is only just starting to kick in. Backing this cable is Facebook’s way of acknowledging that Asian users are important to the continued growth of the social network — and, of course, the company is also communicating to its shareholders that its flagging US and EU growth isn’t a cause for concern.

While it seems quite sensible, it’s actually quite uncommon for web-based companies to invest in infrastructure beyond their own data centers. Google is one of the few exceptions, owning large swathes of the internet’s backbone, and being a member of the consortium that laid the Japan-US Unity submarine cable system. By owning a large portion of the network between its servers and its users, and thus control of the network setup and topology, it can provide much faster (lower-latency) access to its services. Being the most popular destination on the web, I wouldn’t be surprised if this marks the beginning of significant infrastructure investment by Facebook.

Read more about the secret world of submarine cables, or about the $1.5 billion polar Arctic Fibre and Arctic Link cables that will cut London-Tokyo latency by 60ms.