As everything from smartphones to internet-linked appliances and cars get online, the group entrusted with organising the web is running out of the "IP" numbers that identify destinations for digital traffic.

The touted solution is a switch to a standard called IPv6 that allows trillions of internet addresses, while the current IPv4 standard provides a meagre four billion or so.

"The big pool in the sky that gives addresses is going to run out in the next several weeks," said Google engineer Lorenzo Colitti, who is leading the internet giant's transition to the new standard.

"In some sense, we are driving toward a wall. We have to do something, and IPv6 is the only real long-term solution."

The pool of IP addresses is maintained by the non-profit internet Corporation for Assigned Names and Numbers (ICANN), chaired by New Zealander Peter Dengate-Thrush, a Wellington barrister.

In New Zealand, a taskforce headed by Murray Milner has been urging local organisations to prepare for when the supply of addresses on the old IPv4 standard runs out.

Instead of buying up blocks of the remaining addresses, at around US50c (65c) each, the money would be better spent upgrading equipment to IPv6. Organisations not compliant with IPv6 will gradually become invisible on the internet, though with several steps in the supply chain, ordinary users won't immediately feel the shortage.

Dengate-Thrush said that, eventually, the internet will be largely IPv6, bringing a profound change. Where the old 32-bit protocol is limited to about 4 billion addresses, 128-bit IPv6 can have 340 billion billion billion billion.

This would enable even the most mundane pieces of equipment to be connected to the internet so that, for example, lamp-posts can report when their bulbs need changing and every camera will have an IP address and can upload photos automatically.

ICANN has been calling for a change to IPv6 for years but websites and service providers have clung to the old standard from the start.

Said Colitti: "One of the reasons it has taken so long to change is that there is no obvious advantage or killer application for IPv6."

ICANN chief Rod Beckstrom, said the number of addresses possible under IPv6 allows for amounts to 340 "undecillion" (followed by 36 zeroes); enough for a trillion people to each be assigned trillions of IP numbers.

"I guess if we could somehow link an IP address to every atom, we might begin to run into problems," Beckstrom said of IPv6 during an interview in his office in the Silicon Valley city of Palo Alto.

"As far as thinking about the number of objects that humans own and use, we are pretty safe."

With about seven billion people on the planet, the IPv4 protocol doesn't allow for everyone to have a gadget with its own online address.

The situation has been likened to not having enough telephone numbers for everyone.

Once the supply of IPv4 addresses ICANN distributes to five centres around the world are gone, computers and other gadgets might have to start sharing instead of having unique identifying numbers.

Said Colitti: "You will start to share with your neighbours, and that causes problems because applications can't distinguish you. If your neighbour ends up in a blacklist, you will too."

"The internet won't stop working; it will just slowly degrade," he said, explaining that systems would eventually have trouble handling multiple connections on shared addresses. "Things will get slower and flakier."

New websites or online services stuck with shared IP addresses wouldn't perform as well as pre-existing offerings that have numbers all to themselves.

The effort and expense of changing to IPv6 would fall mostly on service providers, websites and network operators that have to make sure systems can handle the new online addresses and properly route traffic.

Consumers, for the most part, shouldn't notice the switch since IP numbers would still appear to them as words and domains, such as icann.org.

Some people might need to update routers or modems that connect computers to the internet.

Google, Facebook and other major internet players will add IPv6 addresses to their systems in a one-day trial run on June 8 so everyone involved can check for trouble spots.

In a worst-case scenario, running out of IPv4 addresses with no switch to IPv6 would mean new gadgets wouldn't be able to connect to the internet because addresses weren't available, according to ICANN.

"Ideally, people will see nothing," Beckstrom said of a transition to IPv6.

But, "if enough networks don't move to IPv6," he continued, "people could literally see nothing because they can't connect the next iPad, iPhone, or whatever."

IPv6 allows for seemingly limitless innovation in the internet as well as addresses enough for sensors in anything from chairs and thermostats to individual bottles of wine in a cellar to signal when vintages peak.

Beckstrom said a full shift to IPv6 would take years, with the remaining stock of IP addresses being allocated to support the transition.

- AFP