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

[Hitoshi Asaeda <[e-mail]>]

Hi Behcet,

>> >  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?

Ok, then I change it to "when it subscribes a multicast channel".

>> > 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.

Ok, I understand.
This consideration may be addressed with various approaches.
Our current proposal is in line with the concept of minimum protocol
modification, hence I'd propose the following changes.

There is a statement in section 5.1;

   An MLD proxy requires that the upstream and downstream interfaces
   MUST be statistically configured.  As well, MAG MUST configure an
   upstream interface that is the interface MLD Report messages are sent
   to LMA and downstream interfaces that are the interfaces MLD Report
   messages are received from mobile nodes.  This upstream interface is
   the M-Tunnel end-point at the MAG.

and I'll append the following sentence;

   Whether MAG acting as an MLD proxy connects to a single or multiple
   LMAs, M-Tunnel for the MAG MUST be established with one LMA.

Also, I'll change a paragraph in section 5.2 as follows;

   Because of its implementation or operational costs, operators may not
   want to support PIM-SM on MAG.  However, an MLD proxy requires to
   statically configure its upstream interface, which is an M-Tunnel as
   specified in Section 5.1, to receive all multicast data. It also does
   not allow multiple incoming interfaces. Hence even if MAG acting as
   an MLD proxy connects to multiple LMAs, it cannot establish with
   multiple M-Tunnels for each LMA. Therefore, if operators decide to
   support the case that 1) an upstream interface for the optimized
   multicast path is NOT an M-Tunnel to LMA but other interface, and
   should be dynamically selected by MAG according to the optimized
   routing path, or 2) MAG should establish multiple M-Tunnels for
   different LMAs, and an incoming interface should be decided by the
   RPF check, then MAG MUST act as a PIM-SM router.

There might be some discussions for this, but I think above sentences
would become a reasonable start.
I'd appreciate any input, especially from providers and operators.

Regards,
--
Hitoshi Asaeda