[AG-TECH] Response to AG Retreat Day 1 and 2

Brian Corrie brian.corrie at newmic.com
Tue Oct 1 14:18:23 CDT 2002


Hello all,

First, thanks to Ivan and the group at Argonne (and everyone else involved)
for their work. I think the concept of AG 2.0 is a good direction. Exactly
how to get there from here becomes the interesting question.

We were at least one of the sites that was causing some echo today so I
didn't want to ask questions on the spot... So here are some questions after
some reflection. Hopefully our sound kinks will be worked out, we will see
tomorrow 8-)

Ivan, can you comment in more detail on where this architecture is at in
terms of design and implementation? It sounds like you have been
experimenting with bits and pieces of it. At the same time you have stressed
that you are in the design/exploration stage. Where are things at and what
pieces of the puzzle are more advanced?

Our interests are primarily around the service model, the docking mechanism,
and the extensibility of both. In the presentation on services you mentioned
that the group is re-engineering Voyager as a service. Is this the only
service that is being explored (I know you asked the AG community for
others)? Is it being re-engineered to a draft service spec or are you
experimenting with services through the use of Voyager? The stanard AG
services that we use today are currently audio, video, dppt, voyager, and
perhaps a few others. These seem like the obvious first choices for
conversion to AG 2.0 services. Are any of these being considered and worked
on other than voyager? Are these actually the type of things that you are
thinking of as the initial services for AG 2.0?

As Luc's comment indicates, it isn't terribly clear at what level a service
should be provided. Does a venue advertise a H263 video service over RTP,
does it advertise a vic service (which requires vic on each end), or does it
advertise something else entirely? I agree with Allan in that streams should
not necessarily be tightly coupled to applications. This opens up a whole
realm of interesting (and possibly very messy) combinations of services that
transform media streams. Which leads nicely into the next two points...

One of the nice things about the AG 2.0 architecture (if I understand it
correctly) is that it should be possible to support all of the above
approaches to service delivery. The bad thing about this is that it can lead
to fairly significant divergence in what an AG venue looks like.

In such a dynamic and heterogeneous environment, is there any thought going
into higher level aspects of managing this space? This would presumably be a
service that a venue could provide. What I am thinking of is something that
takes into account both the services provided by the venue and the
capabilities of the connecting node and making intelligent decisions about
what technologies to use. For example, if I am connecting via my AG room then
I get the appropriate media streams and applications started automatically.
If I am connecting via my PDA then I get the low bandwidth video feed (if
such a thing is provided). If I am connecting via my CAVE then I get the
appropriate media for that technology... This would take away the
requirements at the user end for technical expertise and provide a
significant increase in the quality of experience for the end user. I saw a
mention of brokering capabilites in the Venues presentation yesterday. Is
this what you were thinking along those lines? This "quality of experience"
is an area where we are currently working and I would be interested in
exploring how we might be able to contribute to AG 2.0. Perhaps add some of
that human factors "stuff" that we were talking about!!!

Cheers,

	Brian
 

> -----Original Message-----
> From: Luc Renambot [mailto:renambot at cs.vu.nl]
> Sent: Tuesday, October 01, 2002 7:33 AM
> To: 'Allan Spale'; ag-tech at mcs.anl.gov
> Subject: RE: [AG-TECH] Response to AG Retreat Day 1
> 
> 
> 
> Plenty of nice ideas from Allan... To continue on the stream
> subject, I would really like to see VIC and RAT put in pieces,
> putting a RTP stack in the center of an AccessGrid SDK. I should
> be able to discover and register to data streams coming from 
> a specific venue: for instance I send that video stream to a
> trans-coding service for unicast transmission to PDAs (EVL Continuum)
> or this high-resolution MJPEG stream for hardware decoding (RTPtv),
> or this group of streams for regular display, and so on. It 
> would allow
> things like "I don't display anything coming from ANL" or "I group
> together all the active videos" ("active" should be defined at will)
> or "I bridge all the audio streams coming from 130.xxx.xxx.xxx".
> Also if I discover a 3D stream in the venue, I start a 3D viewer....
> 
> Luc
> renambot at cs.vu.nl
> 
> 
> ] -----Original Message-----
> ] From: owner-ag-tech at mcs.anl.gov 
> ] [mailto:owner-ag-tech at mcs.anl.gov] On Behalf Of Allan Spale
> ] Sent: Monday, September 30, 2002 21:08
> ] To: ag-tech at mcs.anl.gov
> ] Subject: [AG-TECH] Response to AG Retreat Day 1
> ] 
> ] 
> ] Hello,
> ] 
> ] Based on some of the discussions that were had this morning, 
> ] 
> ] .....
> 
> 



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