Re: Comments on draft-koodli-ipv6-in-mobile-networks-02.txt

[Rajeev Koodli <rkoodli@cisco.com>]

Hi Behcet,



On 4/19/10 12:14 PM, "Behcet Sarikaya" <behcetsarikaya@yahoo.com> wrote:

> Hi Rajeev,
>   My comments on 
> Section 3.2 NAT Placement in the mobile networks
> 
> This section nicely narrates the story of GI-DS-Lite as the centralized
> NAT versus DS-Lite as the distributed DS-Lite. It reads nicely but I found in
> it too much emphasis on billing and accounting aspects while it lacks emphasis
> on other aspects (more meaty? aspects at least as much as I am interested).

DS-Lite is not presented as a distributed NAT solution in the document.

Many mobile providers do care for subscriber management. For them, it is
important to be able to do harmonized billing and accounting. With respect
to NAT itself, which introduces binding state between addresses, it is
important to be able to harmonize NAT state with subscriber billing and
accounting.

> 
> For example, one very important feature of DS-Lite is to have an IPv6-only
> network thus savings on IPv4 addresses. This is not mentioned.
> Next, why currently mobile operators do not have much interest on DS-Lite is
> not mentioned.

Clarification: this ID is *not* about evaluating pros and cons of each of
the available transition mechanism. It is about considerations that arise
when deploying IPv6 in mobile networks.

To your point about DS-lite itself, it is perfectly fine in residential
broadband networks. For mobile networks, having a tunnel termination at the
UE (host) is considered undesirable. The 3GPP TR on IPv6 transition looks at
some of the variants FYI, and that document may be a good place for your
questions. 


> 
> On the centralized NAT or GI-DS-Lite, firstly, the identification of
> GI-DS-Lite as the centralized NAT approach is very useful because it was not
> clear reading the GI-DS-Lite draft.
> 
> However, one important aspect of GI-DS-Lite is that it no longer requires an
> IPv6-only network and therefore no IPv4 address savings which is not mentioned
> in the draft.

I did not follow this. Care to elaborate?

Regards,

-Rajeev

> 
> Regards,
> 
> Behcet
> 
> 
>