Subject: RE: NEMOv4-aware FAs (was: [nemo] Soliciting comments on draft-ietf-nemo-v4-base-00.txt)

From: "Tsirtsis, George" <[email-masked]>
Date: Tue, 28 Mar 2006 07:20:32 -0800

Sure, I will work on this. I will contact you offline to get this
started.

Thanks
George

-----Original Message-----
From: Alexandru Petrescu [mailto:[email-masked]] 
Sent: Tuesday, March 28, 2006 9:38 AM
To: Tsirtsis, George
Cc: [email-masked]
Subject: Re: NEMOv4-aware FAs (was: [nemo] Soliciting comments on
draft-ietf-nemo-v4-base-00.txt)

George, thanks for the valuable comments.  Let me separate the FA
discussion in a different thread.  Basically, co-authors and myself 
would be supportive for an additional NEMOv4-aware FA document, but 
separated from the current spec.  We tried to keep the current spec 
simple and essential, keeping the opportunity open for FA enhancements.

Tsirtsis, George wrote:
> The draft makes no attempt to incorporate Foreign Agents into the 
> solution. Why is that?

In an initial un-published version of the document we've extensively
treated some FA enhancements for NEMOv4.  That included some new options
and messaging.  But we wanted to keep the base spec simpler.

> I think it would be trivial to add FA support for mobile routing and 
> avoid the MR HoA to HA tunnel when FAs are used.

Eliminating the MN-side tunnel by using FA support would be indeed an
advantage.  But in terms of spec size it will certainly be a lengthening
factor.

> The tunnel is a good idea when we are dealing with RFC3344 FAs but 
> there is no reason not to get rid of it when the FA knows about 
> mobile routing. The draft also does not discuss agent advertisements
>  for HA and FA which can be used to let the MN know whether Mobile 
> Routing is supported or not.

Indeed, it doesn't.  Co-authors and myself think FA would be a valuable
feature to add, but as a separate document, especially knowing that
during the last meeting it was stated that the current document is ready
for IESG.

If you're interested in writing an FA NEMOv4 document I'd be supportive.
  If you need I can send the initial FA text we had.  Reviewing back and
forth can happen.

> 3.  Requirements
> 
> .... o  The Mobile Network should be supported using Foreign Agents 
> that are compliant to RFC 3344 without any changes.
> 
> 
> GT> While it is important to be able to work with RFC3344 FAs, we 
> should also have extensions to FAs that make this better. ...

Ok.

> 7.  Data Forwarding Operation
> 
> For traffic to the nodes in the Mobile Network, the Home Agent MUST 
> perform double tunneling of the packet, if the Mobile Router had 
> registered with a Foreign Agent care-of-address.
> 
> GT> As I already said IMO this is not acceptable and there is no 
> reason why the FAs can not support mobile network and avoid the 
> additional tunnel.

It can.  But the base initial step should be that the MN should do it.
Would you agree.

Alex