A friend asked me what I thinks of IPv6 so I gave him a “short” answer. A modified version as below:
There isn’t really much IPv6 applications driving it right now. The main advantage is still “more public IP addresses”, But to be fair, there is no contention in the community that IPv6 will come. It is only a matter of time when we run out of IPv4. So the right question is asked is “When”, not “Why”.
The “when” question is unfortunately, a crystal ball question : 10 person will give you 10 different answers. If the current growth rate for IPv4 address remains constant, then we will have sufficient IPv4 address until 2020. However, historically, network growth is an exponential curve, not a striaght line. In otherwords, once a technology reach critical mass, it will surprise us and hit us very fast while we scramble to put the service in place.
Likewise, I believe IPv6 will be the similar, but I am not sure what the driver will be. It could be 3G, it could be wireless network, it could be home networking, it could be smart sensor network, it could be GRID and P2P computing, it could be IP core network aka NGN, convergences etc etc.
But whatever the driver is, I dont think it is anything we have now (ie, dialup, broadband, hotspot, etc). We already know what we have now and the growth rate don’t show that kind of demand. It will be something new so we just have to watch out.
Thus, IPv6 may come anytime between 2005 to 2020.
But in my opinion, it is probably earlier then later, perhaps 2008 to 2012. It is still quite far away but considering how much changes you need to do to the network to move to IPv6 (estimation of the transition take 2-3 years), working backwards, start to do some planning in next two year is a good idea.
It need not be an elaborate transition plan: it could be as simple as “if possible, purchase dual stack IPv4/IPv6 routers”. That is what US government do: From next year onwards, they will not buy anything equipments that don’t support both IPv4 and IPv6 although they only expected to move to IPv6 in 2008 or later.
