Comcast believe they need IPv6, as soon as possible, just to manage their cable modems. At the moment that is a problem, because you need DOCSIS 3.0 to support IPv6, and that is very new. You may argue that Comcast were mistaken, and that there are better ways to do it, but they don't seem to think so at the moment. (I could find citations for these statements, but I've got a meeting in a few minutes so I beg your forbearance). NAT is not the answer, because of SIP, if nothing else. It can be argued that the last thing the Internet needed was another NAT unfriendly protocol, but that is what SIP is. I happen to like SIP a lot---at least it is much preferable to the alternatives---and the current directions are very much in favour of SIP. But, essentially SIP + NAT = Does not work. If your application level gateway has to look inside a packet and rewrite it because of NAT, *and* you are using encrypted transport (SIPS), you are out of luck. Alas, most SIP phones don't yet support IPv6. (/me grinds teeth.) The sky may not be falling, IPv6 may not be perfect, but I still think we need to adopt it sooner rather than later. -- Michael Newbery IP Architect TelstraClear Limited