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

["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

NOTICE AND DISCLAIMER
This e-mail (including any attachments) is intended for the above-named person(s).  If you are not the intended recipient, notify the sender immediately, delete this email from your system and do not disclose or use for any purpose.  
 
We may monitor all incoming and outgoing emails in line with current legislation. We have taken steps to ensure that this email and attachments are free from any virus, but it remains your responsibility to ensure that viruses do not adversely affect you. 

EE Limited
Registered in England and Wales
Company Registered Number: 02382161
Registered Office Address: Trident Place, Mosquito Way, Hatfield, Hertfordshire, AL10 9BW