comments : draft-ietf-v6ops-3gpp-analysis-00.txt

["BELOEIL Luc FTRD/DMI/CAE" <luc.beloeil@rd.francetelecom.com>]

Hi Juha, 

Thanks to have update the draft !

I still have the same comments on 4.2 paragraph. 

1- a UE that uses IMS services must contact IMS devices over IPv6
(because IMS is IPv6-only). I agree.
2- Nevertheless a UE that uses IMS services could also be dual-stack
(even if it does not use its IPv4 stack to contact IMS devices)
3- As pointed out in section 2.2 and 3.1, DSTM could also be used so as
to send IPv4 datagrams over IPv6 in IPv6 PDP Contexts.
4- when that dual-stack UE is connecting to an IPv4-only node in a
IPv4-only network through IMS, I argue that NAT-PT can be avoided by
using DSTM.

I understand that DSTM might not be easy to set-up inside 3GPP networks
but that is an alternative to NAT-PT. 

Perhaps that 3GPP does not want that such transition mechanisms involve
UE but only network ?

Regards,

Luc