On 12/04/2008, David Woodhouse <[EMAIL PROTECTED]> wrote:
>
> On Wed, 2008-04-09 at 16:13 +0100, Peter Bowyer wrote:
> > On 09/04/2008, David McBride <[EMAIL PROTECTED]> wrote:
> > > Dave Crossland wrote:
> > >
> > > > The BBC-vs-ISP bandwidth issue could be resolved by the BBC dropping
> > > > DRM so that the ISPs can cache the data.
> > >
> > > The ISPs who are anticipating financial hardship are more concerned
> with the
> > > cost of bandwidth between their network and home ADSL users, and _not_
> between
> > > their network and the outside world.
> > >
> > > This is because they are charged a metered rate by BT for all the
> traffic they
> > > relay over BT's ADSL network.
> > >
> > > Thus adding data caches to their network wouldn't solve their
> immediate problem.
> >
> > Indeed. But BTW could do it for the benefit of all of its resellers.
>
> It doesn't work like that. You have a pipe which runs all the way
> through BT's network to your ISP. Even if the content in question were
> somehow cached on a machine in your local exchange, that doesn't really
> help because it doesn't see your IP traffic at all. Traffic from that
> cache to you would go all the way out to your ISP and then back down
> your pipe.
If it were all doing using HTTP it would be easily cached, of course, as you
can do this with a proxy server, either a configured-in one as used on
corporate and educational networks, or as a transparent proxy.
It's the easiest thing in the world to control the cache, as you just add in
a few lines to the HTTP header, viz in PHP:
Header ("Last-Modified: " . gmdate("D, d M Y H:i:s",mktime (0,0,0,1,1,2000))
. " GMT"); // Date in the past
Header ("Expires: Mon, 26 Jul 2040 05:00:00 GMT"); // In other words...
never expire it
Header ("Cache-Control: max-age=10000000, s-maxage=1000000, public"); //
I have to say that I am not a fan of transparent proxy caches, but if the
ISP are going to moan about BBC 'streaming' then there is a very simple
three line (plus proxy server) fix...
--
> dwmw2
>
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--
Please email me back if you need any more help.
Brian Butterworth
http://www.ukfree.tv
