Re: [multimob] draft-asaeda-multimob-pmip6-extension-05

[Behcet Sarikaya <[e-mail]>]

Hi Hitoshi,


> Hi Behcet,
> 
> >   I read your draft and have some comments.
> >  In section 3.3, you say MN sends MLD Report upon multicast data
> >  reception. Why? 
> > I think there is something wrong in that  sentence.
> 
> I cannot understand what's wrong here?

May be you meant in order to join a group?

> 
> > Your draft  is long and detailed and on top of that it mentions [9] 
> >  draft-asaeda-multimob-igmp-mld-mobility-extensions-03.txt as normative 
> >  reference. 
> 
> Right, that draft should be informative reference. I'll move  it in the
> next revision.
> 
> > What I am more curious about is how your  draft solves the tunnel convergence 
>
> > problem. I don't think it is the  M-Tunnel because as you mentioned
> > M-Tunnel is MAG-LMA tunnel as in [2],  i.e. RFC 5213. 
> 
> Single M-Tunnel is established between LMA-MAG and  dedicated to
> MLD messages and multicast data transmission. It is shared by  all MNs
> attached to a MAG. It's not established per MN, unlike  rfc5213.

see below.

> 
> > I don't think it is MAG as PIM-SM router as you mention  that
> > operators would not 
> > like it. Sorry but I could not find a  specific solution proposal in
> > your draft. 
> > Maybe I missed  something.
> 
> It is one of the possible ways for multicast services in  PMIPv6
> domain. I cannot find the reason to prohibit PIM-SM capable MAG.
> In  fact, since an incoming interface can be set up by the PIM-SM
> capable MAG, it  gives the chance of localized routing and source
> mobility without any  protocol modification.
> Giving the possibility of a PIM-SM capable MAG would  be rather
> positive in my feeling.

Yes, if PIM-SM can be deployed at all MAGs, tunnel convergence problem won't 
happen. This is kind of like local routing.

> 
> > How relevant your Section 7 is  to the tunnel convergence solution? I
> > have a feeling that it is more  relevant for handover optimizations
> > work item we have.
> 
> I think  sharing single M-Tunnel by all MNs address the tunnel
> convergence problem. If  you don't think so, could you tell me what the
> problem is?

No because the tunnel convergence problem happens due to multiple LMAs and MNs 
connected to multiple LMAs joining the same group like G1. Then LMAs deliver 
multicast data from G1 to the MAG and MAG just replicates the data to each 
member MN.
M-Tunnel does not address this problem.

I hope this is clear. 

> Regarding  handover, I believe our proposed extension is not only
> simple and in line  with the standard functions, but effectively 
> provides seamless  handover.
> I don't deny someone will propose other mechanisms or extensions  with
> a different view for the optimization in the later phase, such  as
> proactive handover. But their mechanisms might require more  extension
> or additional functions to give more optimization. Our proposal  could
> be defined as the base extension for them, I  guess.


You need to show how relevant it is to the tunnel convergence problem. Right now 
I cannot see it.

Regards,

Behcet