Re: comments on draft-durand-v6ops-assisted-tunneling-requirements-00 .txt

[Pekka Savola <pekkas@netcore.fi>]

On Wed, 14 Apr 2004, Karim El-Malki (HF/EAB) wrote:
>    Althought the main focus of this document is the ISP scenario,
>    assisted tunneling is applicable in all the other scenarios:
>    unmanaged, enterprise and 3GPP.
>    ...
>    In 3GPP networks, assisted tunneling can be used in the context of
>    dual stack UE connecting to IPv6 nodes through a 3GPP network that
>    only supports IPv4 PDP contexts [3GPP, 3.1].
> 
> There seems to be a contradiction when considering 3GPP networks,
> since the customer does not have a NAT in the customer equipment
> (i.e. mobile terminal). Therefore the tunneling can be terminated
> within the mobile operator's network and never goes through a NAT.
> That's a good thing since we wouldn't have to pass even more traffic
> (v6 tunnelled traffic) through NATs in this scenario. For the same
> reason the following consideration on ISATAP does not apply to 3GPP
> networks (also described in the draft reference [3GPP]):
> 
>    7.3 ISATAP
> 
>    Similar considerations as Teredo, section 7.2, applies to Isatap.
>    However, as Isatap can not work accross NAT, it is of much less
>    interest in the framework of this document.
> 
> I think that to make this draft applicable to 3GPP networks some
> substantial changes would be needed such as the removal of the NAT
> assumption.

I do not see the contradiction.

The document just basically says, "we want to support all the 
scenarios, whether it goes through a NAT or not".

In the case of 3GPP, it doesn't go through NAT, but the requirements 
are equally applicable.

On the other hand, as I read it, section 7.3 basically says "ISATAP 
could be supported, but as it is not applicable through a NAT, it 
would only be usable in the scenarios where there is no NAT, so it 
might not be worth the effort plug ISATAP support in the tunnel 
server clients/servers."

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings