Subject: RE: caching on-demand transmissions

From: [email-masked]
Date: Tue, 4 Nov 1997 09:33:08 -0500

Right. I really fail to see the point in using multicasting for
on-demand applications.

On-demand inherantly means one recipient. If you have to replay recorded
MBone content, it should be done with something similar to RealVideo.
The only way multicasting is useful for on-demand application is when
people gather in a viewing room and they get recorded content to play on
a screen in that room. But here, multicasting is done at a totally
diffrent level :-)

This would mean MBone and recorded content appear rather imcompatible
and the MBone has to be used for something else, such as conferencing.

If I have proven myself to be in the dark with this message, I'd be
happy to be brought out to light.

Regards,
Yves Lepage

> -----Original Message-----
> From:	[email-masked] [SMTP:[email-masked]]
> Sent:	Tuesday, November 04, 1997 6:13 AM
> To:	[email-masked]
> Cc:	[email-masked]
> Subject:	caching on-demand transmissions
> 
> > 
> > 
> > I haven't read the article or seen the direct quote, but I believe
> what
> > Jeff's comments are in reference to are "on-demand" viewing.  Mbone
> does
> > allow rebroadcast (such as Munich IETF rebroadcast for US
> audiences).
> > However, I can't think of the advantage of using mbone for on-demand
> > content like music clips, unless you can corral several users'
> requests
> > together into one multicast.  This is an old can of worms though,
> nothing
> > new here.
> > 
> > Jim
> > 
> 
> That might be sensible only if we had some bigger caching built
> into mrouters. %-)
> Actually there could be one way caching, that would synchronise users 
> requests, and the other way - 'object caches' that would cache the
> popular
> contents that's frequently demanded. this way transmissions
> 'on-demand'
> would not pollute 'the whole mbone'.
> but this is probably not about mbone any more ...
> 
> --w

---

From: Petri Helenius <[email-masked]>
Date: Tue, 4 Nov 1997 18:24:29 +0200 (EET)

> a screen in that room. But here, multicasting is done at a totally

I think our definition of on-demand is different. To me on-demand
means "just now or in the very near future". Like if I order a pizza,
it gets delivered in the next 30 minutes. If I want to see a movie, I
can wait 5 or 10 minutes for it to start. It's less than driving to a
video rental shop just to figure out that the movie I wanted was
already taken. 
 > happy to be brought out to light.
Hope you got some more light now :-)

Pete

---

From: Amancio Hasty <[email-masked]>
Date: Tue, 04 Nov 1997 09:24:09 -0800

It depends, on the on-demand usage of the users 8)

The commercial motivation for supporting ip multicast is that it 
allows the servers to support many more users than they typically
can.
	Amancio

---

From: Petri Helenius <[email-masked]>
Date: Tue, 4 Nov 1997 20:06:55 +0200 (EET)

> allows the servers to support many more users than they typically

And, in my opinion more importantly, it allows the network to serve
many more users than it would othervise be able. Remember that average
US ISP has less backbone capacity than what a single-CPU Pentium PC
could saturate.

Pete