Re: [v6ops] I-D Action: draft-ietf-v6ops-ipv6-roaming-analysis-02.txt

[GangChen <[e-mail]>]

Ross and Nick,

The draft doesn't intend to advocate any deployment mode.
To be clear, "dual-stack deployment is recommended in most cases" will
be removed at the next update.

Gang

2014-08-05 23:53 GMT+08:00, Heatley, Nick <[e-mail]>:
>>So there's an argument to remove "dual-stack deployment is recommended in
>> most cases" from this draft, particularly if it has already been discussed
>> and agreed not to promote any solution.
>
> Agree.
>
> Also the standards statement:
> "A UE which is IPv6 and IPv4 capable shall request for PDN type IPv4v6".
> does not mean that the UE is placed into a dual stack mode of operation. It
> is signalling to the network that it can support all modes.
> (We desire the UE to request IPv4v6 in the home network and we can let the
> core network push the UE to IPv6-only mode of operation.
> When on legacy small-cells, where the access-points do not support the new
> PDN types, the device can gracefully fallback to IPv4, if it requests
> IPv4v6.)
> Nick
>
> From: v6ops [mailto:[e-mail]] On Behalf Of Ross Chandler
> Sent: 05 August 2014 12:33
> To: [e-mail]
> Subject: Re: [v6ops] I-D Action:
> draft-ietf-v6ops-ipv6-roaming-analysis-02.txt
>
>
> On 5 Aug 2014, at 11:53, Jouni
> <[e-mail]<mailto:[e-mail]>> wrote:
>
>
>
> On Aug 5, 2014, at 1:28 PM, GangChen wrote:
>
>
> 2014-08-05 0:31 GMT+08:00, Mikael Abrahamsson
> <[e-mail]<mailto:[e-mail]>>:
>
>
> Section 7, discussions,  says "dual-stack deployment is recommended in
> most cases".
> Is that still the consensus position?  Going straight to single-stack IPv6
> is looking very viable now
> when the UE supports a method of providing translated IPv4 access over the
> IPv6 PDP/PDN
> connection.
>
> I don't think there is consensus here. The draft could point out pros and
> cons with each approach.
>
> I'm not a fan of dual-stack deployment. However, I have to point out
> if you take look at TS23.060 or TS23.401, you may find the sentence "A
> UE which is IPv6 and IPv4 capable shall request for PDN type IPv4v6".
> GSMA quotes the similar language from 3GPP for roaming guidance.
> Therefore, that is at least a consensus in other SDOs.
>
> The draft intends to state the issues and potential workarounds in
> various scenarios. Argument of selection of dual-stack or IPv6-only
> may not be the goal of the draft.
>
> We had this discussion a long ago.. and back then we agreed not to promote
> any specific solution (like XLAT etc) but just give facts how different
> approaches work.
>
> - Jouni
>
>
> The TS23.975 recommendations do allow for a second strategy. I can't find
> TS23.975 explicitly saying dual-stack is preferred or recommended over
> single stack.
> Although at the time they were writing it they were probably implicitly
> assuming that. TS23.975 mentions DS-Lite, NAT64 and BIH but was too early
> for 464XLAT, or MAP-T/E.
>
> "The second strategy, consisting of providing the UE with IPv6-only
> connectivity, can be considered as a first stage or an ultimate target
> scenario for operators."
>
> So there's an argument to remove "dual-stack deployment is recommended in
> most cases" from this draft, particularly if it has already been discussed
> and agreed not to promote any solution.
>
> BR
> Ross
>
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