On 23 nov 2007, at 16:51, Norbert Bollow wrote:
I think I'm getting convinced that your "modified NAT-PT" approach http://www.ietf.org/internet-drafts/draft-van-beijnum-modified-nat-pt-02.txt is essentially the way to go.
My only concern is that there is not much time left until IPv4 address depletion will start causing real problems, and we don't even have a "finished" RFC for "modified NAT-PT" yet.
How do you see the timeline with regard to getting more feedback on this I-D, publishing the RFC, implementation and deployment?
That's a good question. I haven't paid attention to any instances of the IETF moving fast with a protocol RFC, so I can pretty much only guess. But I'd say it would take about a year to reach consensus and a stable specification if there is sufficient interest, except that carving out a block of IPv4 space for the IPv4-to-IPv6 part could take more time.
As for implementations: the IPv4-to-IPv6 part requires some changes to existing translators. The IPv6-to-IPv4 part probably doesn't, but I'm not completely sure about that. On the (IPv6) host side, the IPv4-to- IPv6 part can work for the most part without changes. But the IPv6-to- IPv4 part requires changes fairly deep inside the TCP/IP stack, which will probably take a considerable amount of time to roll out on operating systems like Windows and Mac OS even if Microsoft and Apple give this some priority. The problem here is that you don't get much benefit until both translators are deployed in the network and operating systems are modified to make use of them.
Alternatively, individual ISPs could roll out translators in their network and provide customers with CPEs that perform IPv4-to-IPv6 translation as outlined in section 5 of the draft. These CPEs only have to implement SIIT without the NAT part plus some address management, so implementing that wouldn't have to take forever. The fact that both ends are under the control of the same entity will certainly help get things off the ground faster.
I would guess it's reasonably possible (but not a given) to have something on the market in 2 years