Re: [v6ops] reclassify 464XLAT as standard instead of info - double stack coexistence

[Alexandre Petrescu <[e-mail]>]

Le 25/09/2017 à 13:07, JORDI PALET MARTINEZ a écrit :
> Many operators have not CGN yet,

When they get it it wont be an IPv6 CGN, please.

Because CGN means NAT.  We dont want NAT in IPv6.

> so IPv6-only solutions even if they require NAT64

Dont assume operators to come up with an IPv6 CGN, please.

So operators wont require NAT64.

Let operators do IPv4 NAT, CGN with IPv4, and native non-translated IPv6
all the way.

> are more efficient (you have even open source for NAT64) and IPv4 
> usage of a few IPv4 public addresses scale much better with NAT64 
> than in CGN.

Again: dont translate IPv6 to IPv4 or vice-versa.  It becomes a mess,
apps dont work.

> And of course, if you have IPv6-only-access it means more and more
> of your traffic is going thru to IPv6 destinations, so you have less
> and less usage of any transition stuff.

Yes, that way.

> In addition to that there are implications in terms of battery and 
> radio bandwidth (keep-alives for CGN), which have much less impact
> if the access network is IPv6-only.

Well, I am not sure what you mean?

You seem to be using the keep-alive argument (known for some apps to
keem state up in some NATs) to claim that 464XLAT involves the terminal
to consume less battery.

Keep-alives for NAT will kill the battery - yes, so reduce the time you
use IPv4 on the terminal.  If you use IPv6 on terminal for same apps
your battery will last longer.

So I dont understand how NAT keepalives are an argument in favor of a
translation mechanism.

> I’ve not seen any native IPv6 app that gets impacted by transition.

DHCPv6-PD is a native IPv6 app: it runs only IPv6 sockets, and it is an
Application in Android Store.  However, it is impacted by CLAT.  More
precisely: when CLAT runs DHCPv6-PD cant run.

> I agree that transition is always imperfect, one way or another for 
> IPv4, but we need to balance between long-term strategy or staying 
> forever with IPv4.

I agree.

The strategy is: use IPv4 with NAT (if you dont have enough IPv4
publicly routable addresses), and use IPv6 pure at the same time.

In the past there were other strategies like IPv6 growing islands
(6bone), or IPv6-IPv4 translations (6to4).

> Actually 464XLAT is really inexpensive, much less CapEx and OpEx
> than any other transition and even than dual-stack-access.

464XLAT involves some issues with some apps.  It's expensive to update
apps to work with 464XLAT.

Saying that 464XLAT is only part of the network (not in the terminal) is
false - there is CLAT in terminal.

Double-stack (IPv4-IPv6 PDP type, or PPPoE-v4-and-v6 on ADSL) is the 
least expensive.

Alex