The current underlying protocol used for most data transmission is the internet protocol, version 4, aka IPv4. All IPv4 addresses are 32 bits long putting a hard limit on the absolute number of physical addresses that can be supported by the protocol (588.32 million).[1] Within the last decade, this address space has quickly become a scarce resource driven in part by the addition of substantial numbers of international users (India, China), the proliferation of mobile Internet access, and continued expansion of classic PC internet access.

While Network Address Translation (NAT) has given IPv4 a little bit more time, the reality is that it only delays the inevitable transition to IPv6. The most recent predictions done by the Asia Pacific Network Information Centre indicated that we will run out of IPv4 space in February 2011. While one may debate the exact date when the physical network space capacity of IPv4 will be exhausted even optimistic scenarios predict address space exhaustion in 2 years. [2]

IPv6 addresses are a 128 bits long which allows for a much larger physical address space (roughly ten billion billion billion times as many as IPv4). This more advanced protocol also supports a more policy oriented security model, eliminates the need for NAT, and should lead to more efficient network routing.[3]

So, given the clearly problem and potential advantages why hasn't the world already transitioned to IPv6? In one word, money. Current estimates place the infrastructure upgrade necessary to make the transition to an IPv6 environment at roughly $400 billion worldwide. The primary infrastructure that requires the upgrades will be most of the network routers which are in place today. In addition, the addressing scheme and related packet sizes will also challenge existing "workhorse" technologies such as Asynchronous Transfer Mode.[4]

Unlike the metric system, this is a transition to a new standard, that the United States won't be able to simply ignore.