Re: [MEXT] weird idea about flow bindings

["Charles E. Perkins" <charles.perkins at earthlink.net>]

Hello folks,

I've been following some of this discussion from afar, please excuse
if I am not up to speed...

Suresh Krishnan wrote:
> Hi Marcelo,
>
> On 17/05/09 08:58 AM, marcelo bagnulo braun wrote:
> > ok, let me try again because it seems i am failing miserably to 
> > communicate what i want to say (or it simply so broken that people 
> > cannot believe what they are reading :-)
>
> I think it is a cool idea but it is very hard to realize in practice 
> since it needs CNs to be changed.

Right.  This seems very much the point.  If we are going to enable the use
of flow labels, CNs need to be changed.  The application that wants to
have flows will have to run on the mobile and on the CN.

But this seems perfectly fine, even desirable, to me.  Am I missing
something?

For an application that wants to make a flow happen that doesn't
use the flow label, is it somehow imagined that the application will
not have to run on the CN?

> > Suppose now that the app2 in the CN starts a flow to the MN. 
> > According to RFC3697, the CN SHOULD assign a different flow label to 
> > the packets belonging to this flow e.g. to this TCP connection. 
>
> This is the crux of the issue. Almost every implementation I have seen 
> sets the flow label to zero. This falls under the category "A source 
> node which does not assign traffic to flows MUST set the Flow Label to 
> zero.". Add to this the fact that compliance to RFC3697 is completely 
> optional (it is not even mentioned in RFC4294), and this task quickly 
> becomes pretty improbable. 

Implementation of what?  Implementation of Mobile IP?  Implementation of 
IPv6?
I guess the application would have to use something to indicate that the 
flow
label should NOT be zero.  I still am not really seeing what's wrong 
with that.

In brief, since applications today do not use the flow label, I don't 
see what's
wrong with the flow label being zero.  When applications are built that 
need to
use the flow label, they'll have to have operating systems support to do it.

Thanks for any light you can shed on this.

Regards,
Charlie P.