Re: Re the AR draft (http://www.ietf.org/internet-drafts/draft-fair-ipdvb-ar-00.txt)

[Gorry Fairhurst <gorry@erg.abdn.ac.uk>]

On 15/7/03 12:54 am, "borderlt" <border@hns.com> wrote:

> 
> Gorry,
> 
>   I don't know, but I missed the announced re the AR draft.  So, I had not
> read it prior to this afternoon's meeting.  But, I have read it now...
> 
>   I think the unicast problem to be solved needs to be illustrated more
> clearly in the draft.  Address resolution has different purposes for unicast
> and multicast.  For multicast, it relates to determining an address to receive
> on.  The requirements for this seem covered by the draft.  But, for unicast,
> address resolution means figuring out the address you need to send to.  With a
> DVB broadcast, I see three possibilities:
> 
>   (1) A host at the DVB broadcast receiver needs to resolve an address that
> is at the DVB broadcast sender;
>   (2) A host at the DVB broadcast receiver needs to resolve an address that
> is at another DVB broadcast receiver;
>   (3) A host at the DVB broadcast sender needs to resolve an address that is
> at a DVB broadcast receiver.
> 
> Unless you are assuming mesh (which is really not DVB broadcast, and therefore
> is a different scope), (1) and (2) are really the same in that the host at the
> DVB receiver doesn't know the difference.  In either case, the address which
> needs to be determined is the MAC address of the device at the DVB sender to
> which the IP packet should be forwarded (probably a router).  Even if it is
> not a router, some device at the DVB sender has to relay the IP packet back to
> the DVB broadcast channel and this is really the device which then needs to
> resolve the specific DVB receiver MAC address.  This is basically (3).  So, it
> seems like (3) is the problem which needs to be solved.  But, the draft
> doesn't come across that way...
> 
>   Of course, it is possible that I am thinking about the wrong problem.
> Hence my first statement re needing to more clearly define the problem being
> addressed...
> 
> 
> John
> 

Thanks John, I saw you, and thought you were going to say something at the
mic... I'll email the list, in a short while, I agree with you summary.

The draft was put together in a few days to get the ball rolling, based on
some detailed exchanges on multicast resolution between me and Marie-Jose.
The main aim was to get something on the table to start the discussion !!

Gorry