don't decide without thinking it through that you're assigning a customer a /64 a /60 a /56 or even /48. this should be defensible as part of a business plan, otherwise what's the point?
A /48 is defensible. It's the architecturally intended end-site configuration, it is allowed by policy, and, it is a reasonable starting point. There is no real reason to assign less than a /48 to any end-site other than hyper- conservatism due to IPv4-think.
I still haven't seen any good argument for why residential users need /48s. No, I don't think "that makes all the address assignments the same size" is a particularly relevant or convincing argument. We're doing /56 for residential users, and have no plans to change this. Steinar Haug, Nethelp consulting, sthaug@nethelp.no