DVB & all (Re: ipsat BoF)

[Harri Hakulinen NRC/Tre <Harri.Hakulinen@research.nokia.com>]

EXT takei wrote:
> "Walid" == Walid Dabbous <Walid.Dabbous@sophia.inria.fr> writes:
> Walid> there is no written document yet describing the problem.
> 
> During UDLR products development, we do find that DAVIC(*)
> specification is not match UDLR environment. DAVIC defined their
> specification based on broadcasting service. It doesn't have MAC
> address of source node. According to the UDLR internet drafts, source
> MAC address is necessary.

Given that in typical DVB broadcast environment there is
indeed very limited number of source nodes, at least when
compered to number of receivers (1(0) against 1000(0)(0)(0)),
it was desing target in DVB to get rid of source MAC.
Later that was adobted/approved in DAVIC.

(MPEG /DVB TS has also notion of virtual channels (PIDs),
 and if there really exists more than one sender, it is 
 possible and maybe also desirable to map each sender to
 separate virtual channel, ie. perform ARP in ATM style.)

So, in my (and DVBs, I guess) perspective this is possible
desing flaw in UDLR, not in DVB spec. But I am not so
worried about this compared to other issues.

> So, we developed IP encapsulation mechanism into MPEG transport stream
> which can carry source MAC address and other important information. We
> would be happy to present our proposal in Chicago meeting.

Why not, but I am NOT convinced, that this is something that
should be reopenend in IETF, altought you may claim, that
issue should have been handled in IETF in the first place.

> (*) DAVIC is Digital Audio-Visual Council. They have already defined
> IP encapsulation into MPEG transport stream(TS). See http://www.davic.org.

That comes directly from DVB, that is also regognized in
DAVIC meeting minutes about one year ago, I hope.

My worries in this issue generally are the following:

- General system model (for IP access) is missing
  - what kind of tunneling, you don't want
    to implement & support them all in your STB
  - ...
- If there is 1(0) sender(s) and 10000(0)(0) receivers
  - what kind of ARP really works
  - same question for tunneling 

- How to describe IP services in common way in DVB SI
  (Service Infromation "database", that is periodically 
   send in every DVB compliant MPEG Transport Stream)

  DVB usually leaves this kind of issues to interested 
  groups or companies/operators.

- ...

Some references can be found from my earlier mail.
DAVIC specs can be found via 

http://www.davic.org

Other specs you probably have to order via snail mail, see

http://www.iso.org
http://www.etsi.org
http://www.dvb.org

--
Harri.Hakulinen              
@research.nokia.com            Play the Snake 
Visual Communications          http://www.nokia.com/snake/
Tampere/Finland