Re: [v4v6interim] "IPv4->IPv6 is hard"

Xing,

1.
I share the view that,  for ISPs that haven't enough v4 addresses for
all their customers (there will be more and more), charging a higher
price for those that need one or several  global IPv4 address makes a
lot of sense.

It is not in conflict with the fact that ISPs that still have enough v4
space to distribute can also distribute IPv6 prefixes without extra
price.  (Free did in France, using 6rd for that).

I fully agree with Fred and you that, for the coexistence period,
progress on _technologies_ is more than ever a high priority.
The goal must be workable proposals among which ISPs and other Internet
actors will make their choices.

2.
Now, for ISPs that are short in v4 addresses, I believe that merging
IVI and SAM would permit to offer IPv4 connectivity across IPv6
networks at no extra price.

ISPs would for this assign port-restricted IPv4 addresses to ordinary 
customers, with 1:1 correspondence between their IPv6 prefixes and their 
port-restricted addresses. This is what is envisaged in section 6.2 of 
your draft-xli-behave-ivi-00, but in fixing details as proposed in SAM. 
(A new draft on SAM is planned for Minneapolis. It should be easier to
read than draft-despres-sam-00 and draft-despres-sam-scenarios-00 that I 
hastily finished writing for the Montreal meeting).

First simplification compared to the current IVI:
- In SAM, v4 packets that traverse IPv6 domains are for this 
encapsulated in v6 packets.
- Thus, no SIIT translation (and no ALG) is needed between IPv4 and IP 
v6 at the border between the IPv4 and IPv6 domains :-).

Second simplification:
- In an IPv6 address, SAM embeds only the part of the port-restricted 
IPv4 address that is useful to find a route (not the first bits of the 
IPv4 address that are redundant with the IPv6 prefix).
- Thus, as long as the IPv6 prefix fits in 64 bits (which should be the
rule), no new v6 address format is needed :-).

Support of the IPv4->IPv6 scenario:
If a host that supports SAM is attached to an IPv6-only network that has 
SAM gateways at its border with the IPv4 Internet, this host can be 
reached, at its port-restricted IPv4 address, by any host on the global
IPv4 Internet. This is similar to the idea of hosts that directly 
support IVI, the "more interesting scenario" of section 4.8  in your 
draft-xli-behave-ivi-00.

3.
Trying to  take the best of IVI, SAM, and A+P, and possibly merge them,
would IMHO be an interesting subject for discussion in Minneapolis.

Best regards

Rémi

Xing Li   (m/j/a) 10/20/08 9:19 AM:
> Fred Baker 写道:
>> Let's work on the technology.
> Agree. We are working on technology and provide feasible solutions. 
> The market will make the decision. xing
>> 
>> 
> 
> _______________________________________________ v4v6interim mailing
> list v4v6interim@ietf.org 
> https://www.ietf.org/mailman/listinfo/v4v6interim

_______________________________________________
v4v6interim mailing list
v4v6interim@ietf.org
https://www.ietf.org/mailman/listinfo/v4v6interim