Sorry to be a curmudgeon and let me play devil's advocate for a minute. I realize that the address space is enormous; gigantic, even, but if we treat it as cavalierly as you all are proposing, it will get used up. If its treated like an infinite resource that will never, ever be used up as we have done with every other resource on the planet, won't we find ourselves in a heap of trouble? Curtis Michael Dillon wrote:
There seems to be a variance between "It's OK to just give out a /64" to "You better be thinking about giving out a /48". I can live in those boundaries and am most likely fine with either. I'm leaning toward a /56 for regular subscribers and a /48 only for business or large scale customers, and undecided on dial-up. How does this sound?
The starting point is to give everybody a /48 per site. If a business customer has 3 sites, then give them enough space for a /48 for each site. Could be 3 /48s or could be a /46.
But, if you have a lot of residential customers, it is quite reasonable to give them a /56 per site instead. Be prepared for some customers to ask for two /56s because they have a granny-flat or in-law apartment in the house. Also be prepared for some to ask for a /48 because they are running a business at home, or they are technical types who have a their own home network lab.
Your plan for /56 to residential subscribers and /48 to business subscribers sounds perfectly fine as long as your systems have some way to accomodate that grey area, either by recording a /48 against a residential subscriber or counting them as a class of business customer that pays a residential rate.
Charging a customer extra for more IPv6 addresses just will not fly in a competitive market.
--Michael Dillon