RE: FINAL CALL for Feedback on Charter

["Allison, Art" <AAllison@nab.org>]

Sorry was away from email since last week.
I did make a typo  in the text but the hyperlink was correct to A/92, not
A/93.
With respect to contributions, you will find much of A/92 is actually
informative, and addresses the key issues of defining a 'network' , IP
multicast address collisions, MAC addresses and the other work items.  In an
ATSC Transport Stream, the collection of Program Elements referenced in a
single ATSC A/90 Application shall be considered as a distinct IP Network.
More specifically, when making routing policies and IP address scoping
policies, it is the collection of Taps in an ATSC A/90 Application that
shall be viewed as
the Network. Read more about it in A/92.

The scope and work plan does not reference A/92 directly however. It seems
to me that a solution to work item #3 has been developed for the ATSC
transport and defined for that transport. I suggest it be considered first
as a basis for a more general solution and only if it is found lacking
should the group invent a different solution.  The issue is complex and
subtle, and many man hours have been spent on it already.
I suggest adding:

"In accomplishing the work items the preference is use documented
Standard approaches as the basis of a more widely applicable international
solution. Serious consideration is to be given to the approaches
in ATSC A/92 that address part or all of each work item before 
inventing new approaches."

After the list of work items.


Art
::{)
Art Allison
Director Advanced Engineering
NAB
1771 N St NW
Washington DC 20036
202 429 5418


-----Original Message-----
From: Gorry Fairhurst [mailto:gorry@erg.abdn.ac.uk]
Sent: Friday, November 28, 2003 2:43 AM
To: ip-dvb@erg.abdn.ac.uk
Subject: Re: FINAL CALL for Feedback on Charter


OK, so if you think that adding ATSC in the examples, would encourage more
input to this working group, this seems good.
 
- see in line.

On 26/11/03 4:57 pm, "Allison, Art" <AAllison@nab.org> wrote:

> See embedded.
> 
> Art
> ::{)
> Art Allison
> Director Advanced Engineering
> NAB
> 1771 N St NW
> Washington DC 20036
> 202 429 5418
> 
> 
> -----Original Message-----
> From: Gorry Fairhurst [mailto:gorry@erg.abdn.ac.uk]
> Sent: Wednesday, November 26, 2003 11:06 AM
> To: ip-dvb@erg.abdn.ac.uk
> Subject: Re: FINAL CALL for Feedback on Charter
> 
> 
> On 26/11/03 2:03 pm, "Allison, Art" <AAllison@nab.org> wrote:
> 
>> The charter's focus on IP over MPEG-2 being DVB centric is very
> troublesome.
> 
> Where does it say it is DVB-based (it shouldn't)?
> AA> The sentence "The specific focus of the group is on the use of MPEG-2
> transport (examples include the Digital Video Broadcast (DVB) standards:
> DVB-RCS; DVB-S and DVB-T

Insert "and the related ATSC Standards" ?

> ) in next generation networks and is not concerned
> with the development, replacement, or retention of existing protocols on
the
> existing generation of networks. " seems to so imply, as no scope
> requirement to make the solution work on any other transport is mentioned.
> //
> - The DVB examples in  para 1 were brought to the mailing list, if you
wish
> to add other examples of IP over ATSC, then please do suggest some....
> 
> The reference in the second para should include to A/93, as that is the IP
> specific standard (A/90 is even more ATSC specific and maps very closely
at
> the encapsulation layer to ETSI's)

Do you mean "A/93" which speaks of synchronous triggers? - I may well be
missing something, but this seems to be describing synchronisation of data
download rather than IP packet delivery.

> 
>> Certainly the developed method should enable IP over DVB-flavored
>> Transports. However, as an international standard, it should enable IP
> over
>> all flavors of transport, and not discriminate against other flavors.
> ATSC,
>> ISDB and other systems (China's) should be enabled as well.  A generic
>> solution abstracted from the details of transport would seem to have a
> much
>> larger marketplace.
>> 
>> I note that delivery of IP over MPEG-2 has been solved for the ATSC
> 
> - Good, we'd particularly welcome your experience, especially if you can
> contribute experience for using IPv6, especially autoconfiguration.
> 
>> transport, and while the standard is tied to ATSC announcement, that tie
>> could be abstracted, as it is not the heart of the technology. The IP
>> therein is a technically separable layer. The essence of the standard is
> how
>> to deal with the one-way issues that contrast IP over broadcast vs. two
> way
>> over the internet.
>> 
>> See http://www.atsc.org/standards/a_92.pdf
>> 
>> The current scope seems to be one of requiring re-inventing the wheel,
and
>> being narrow while doing so... perhaps a broader view would better serve
> the
>> world.
> 
> By broader do you mean not specific to ATSC;DVB; etc?
> 
> AA>> Correct, over DVB would be one important instance,

That's precisely the intention.

> which can show how
> an abstracted solution may be employed, and perhaps as there is much
> interest in making sure that instance is workable; it may be the first
such
> instance verification.

So, if people with know about ATSC, ISDB-T (and others) can provide
experience, and inputs to the mailing list/internet-drafts, it will help
definitely shape the design and will also keep this group from making
decisions that could raise future compatibility issues with these systems.
That would be most valuable.

>> Art
>> ::{)
>> Art Allison
>> Director Advanced Engineering
>> NAB
>> 1771 N St NW
>> Washington DC 20036
>> 202 429 5418
>> 
>> 
>> -----Original Message-----
> 
> 
> <snip>
>