[Icecast] load constraints

[Dan Stowell]

On 21/05/05, Daniel Ballenger <lpmusix at gmail.com> wrote:
> On 5/20/05, Dan Stowell <danstowell at gmail.com> wrote:
> > Hi Iain,
> >
> > It's a simple answer:
> >
> > > For example, if a box on a 128kbps upload connection is
> > > serving a 64Kbps stream (and not audio-on-demand) - is it limited to two
> > > connections
> >
> > Yes it is.
> >
> > > or is icecast somehow more efficient?
> >
> > No - icecast can't work miracles! The underlying technology of the
> > internet (the way it is at present, at least) only allows a packet of
> > information to be sent to one computer, so icecast needs to replicate
> > each chunk of data for every client it wants to broadcast to.
>
> What about multicast routing?  Doesn't this achieve that?  Just curious :)

Yes, it does, but (and correct me here, please...) I thought there was
a reason that multicast was not achievable - I thought that many of
the routers that make up today's internet didn't support it?

The original TCP/IP protocols didn't include the concept of multicast.
The concept of multicast was added later, and my understanding is
that's why you can't multicast over the general internet - because not
all of the internet supports it.

This article covers the topic nicely:
http://margo.student.utwente.nl/simon/finished/thesis/thesis1/node7.html

I've no idea what the current state of play is wrt multicast support,
and I don't know what the implications would be for icecast... perhaps
someone more knowledgeable will be able to fill in the gaps!

Dan