Subject: Re: [nemo] AAA and NEMO

From: Christophe Janneteau<[email-masked]>
Date: Thu, 13 Feb 2003 10:27:25 +0100

Hi all,

About AAA...

Takeshi TANAKA wrote:
> On Wed, 12 Feb 2003 17:40:16 -0800
> Alper Yegin <[email-masked]> wrote :
> > From network access authentication and authorization perspective,
> > a NEMO network has two type of interactions. One is between the MR and the
> > its point of atttachment to the Internet. The other is between the
> > MNN and the NEMO. These can be viewed as separate and independent
> > from each other. MR can change its point of attachment any time, and this
> > requires new authentication and authorization for the MR. But this should
> > not require new auth/authz for the MNNs currently attached to the network.
> > Similarly, MNNs can come and go, but this should not necessarily require
> > auth/authz actions between the MR and its point of atttachment to the
> > Internet. The current AAA toolset should serve the needs (Radius, Diameter,
> > PANA, 802.1x, etc.)
> I agree.

I agree too...
Just as a side comment I would like to note that, in the general case
where the NEMO does not host its own internal AAA infrastucture (i.e.
AAA server), auth/authz for VMN entering the NEMO will require
signalling to "cross the Internet" two times (NEMO at its current
location -> NEMO's Home AAA server -> VMN's Home AAA server) due to the
NEMO's current location potentially far from its Home network. This is a
different with a regular mobile IP node where the internet will
generally be crossed only once.

Similarly, if the VMN moves within the NEMO from one AR1 to AR2,
re-auth/re-authz at the new AR2 may takes more time if the NEMO's home
AAA server is to be contacted...

So AAA performance in the NEMO case may be worse than for the simple
Mobile-IP case...

> > A movement of MR might change the charging parameters that
> > MR is subject to. If such fluctuations are not to be passed down to the
> > MNNs, the current model of separate AAA stays valid. So, the MNNs can assume
> > that the billing parameters stay fixed between subsequent auth/authz.

I think this chaging or not the charging of VMN is a policy decision to
be taken by the NEMO (MR). In scenarios where the NEMO (serving as ISP
to VMN) is expected to pay more to maintain it connection to the
infrastucture it may want to charge VMN a bit more...
So I think AAA mechanisms should be able to address re-negociation of
charging...to be triggered by the NEMO. Is this a new NEMO-specific
requirement? Is this already supported by AAA?

Of course, there will be other NEMO scenarios where billing will not be
considered (I hope:)

Thanks
Christophe