On Sun, 10 Jan 2010, Mark Smith wrote:
My argument is that if an SP chooses to have the layer 2 edge device perform those security functions, then there is an opportunity for more optimal traffic forwarding via a mechanism like a prefix-redirect. You may not like that design, but you might not have to be making decisions about the tradeoffs between backhaul cost, capex and opex of aggregated-vs-per-POP layer 3 and the influence over customer density and geography that other SPs around the world have to make.
Since some ISPs seem fine with backhauling their PPPoE traffic to a single place in a whole nation, let's (as said in another mail) postpone these hypothetical optimizations to a later update of the document. Right now we need to get IPv6 out the door at all, and still do it securely. I'd rather have the vendors implement the things we have in the document right now, than adding more things in there and postponing deployment further.
-- Mikael Abrahamsson email: swmike@swm.pp.se