Re: [MEXT] Comments on draft-ietf-monami6-multiplecoa-13

[Julien Laganier <[e-mail]>]

Hello all,

On Thursday 14 May 2009, Arnaud Ebalard wrote:
> Hi,
>
> Ryuji Wakikawa <[e-mail]> writes:
> >> From my perspective, MCoA *is* about binding management.
> >
> > From the protocol point of view, we have two choices here.
> > - having special binding for the HoA destination
> > - having flow management to skip RO

I am sympathetic to the view that MCoA is about multiple binding 
management.

It is also my understanding that it would not make sense to create a 
special binding for the HoA: a MIPv6 binding is between a HoA and 
another address, the CoA. It would not make sense to bind the HoA to 
itself.

Thus, I think the functionality we've talking about can be implemented 
in a semantically clean way by "having flow management to skip RO" as 
Ryuji puts it.

> > Since RO is not so important at this point, we should go with the
> > minimal spec which mean the second option.
>
> From my perspective, RO is important.

I agree it is, but as I try to point out above, diverting some of the 
traffic to the HoA while other traffic goes to (one of) the CoA is in 
my view a flow management issue and has nothing to do with multiple 
binding management.

> > You can put all the possible features in the MCoA, but the draft is
> > not discussed in that direction at this stage.
>
> Julien, George, what do you think? Is the feature a simple and
> logical addition for the flow-inding draft? If not, I fail to see how
> it can be specified in an external document extending both (MCoA and
> flow-binding).

I happen to believe that it's reasonable simple to add the feature to 
the flow binding draft (one possibility would be to use BID set to zero 
in a FID to indicate that forwarding to HoA is desired, as I believe 
you proposed earlier.) 

> [...]
>
> > We shouldn't change the semantics of BID for this.
> > We can't modify the spec after completing WG/IETF/IESG LC, but we
> > only accept minor changes for clarification and editorial errors.
> > Otherwise, we will get into endless cycles.
> >
> > Anyway, IMO, your feature can be achieved with the current MCoA
> > spec with flow binding.
>
> I'll let the final word to Julien and George.

Agree with Ryuji on this.

--julien