Re: [v6ops] I-D Action: draft-ietf-v6ops-mobile-device-profile-17.txt - C_REC#9 464XLAT

[Ross Chandler <[e-mail]>]

> On 12 Feb 2015, at 16:27, Alexandru Petrescu <[e-mail]> wrote:
> 
> Hello,
> 
> Thank you for this new version of the draft.
> 
> I have a doubt with respect to the 464XLAT requirement:
>>   C_REC#9:  In order to ensure IPv4 service continuity in an IPv6-only
>>             deployment context, the cellular host should implement the
>>             Customer Side Translator (CLAT, [RFC6877]) function which
>>             is compliant with [RFC6052][RFC6145][RFC6146].
>> 
>>                CLAT function in the cellular host allows for IPv4-only
>>                application and IPv4-referals to work on an IPv6-only
>>                connectivity.  CLAT function requires a NAT64 capability
>>                [RFC6146] in the core network.
>> 
>>                The IPv4 Service Continuity Prefix used by CLAT is
>>                defined in [RFC7335].
> 
> I think this requirement leads to a situation where the network operator deploys IPv6-native-only and IPv4 as an add-on partial feature.
> 
> On one hand, it is encouraging to see native IPv6 and no IPv4.
> 
> On another hand, _partial_ IPv4 support is a temptation which deceives in the end -  it leads to turn off IPv6 and come back to good ol' IPv4 and no IPv6.
> 
> The 464XLAT is partial IPv4 support: does not offer full IPv4 connectivity to the smartphone.  It is not possible to address the smartphone by its IPv4 address - DNS is required; this makes it impossible to make a VPN tunnel, or Mobile IP.  One can not a deploy a wireless IPv4 router along the road in a remote area, for example.

Alex,

Are you saying all VPNs impossible or just ones not that don’t go through NAPT because they don’t use TCP/UDP or something else? Openvpn and IPSec over TCP/UDP work. In the pure IPv4 case their can also be problems with PPTP if the CGN doesn’t have an ALG.

> This leads to a situation where the operator requires end user to switch to another APN which is less IPv6.
> 
> I think it is not a happy situation.
> 
> I would  suggest to qualify this requirement by another requirement. This initial requirement would state that _first_, before any v4-v6 conversion mechanism is considered, both the network and the end user MUST implement a native IPv4 stack and a native IPv6 stack (not say 'dual' stack, which is much overloaded).
> 
> We dont want to block IPv4 use when IPv6 arrives.
> 
> Alex

Perhaps it could be clarified in C_REC#9 that the IPv6-only deployment context refers to the 3GPP device? The data APN it accesses could support IPv4, IPv6 and dual-stack IPv4v6 PDP/PDNs.




BR
Ross