backbone transparent proxy / connection hijacking

Tue Jun 30 21:47:39 UTC 1998

> I do think that it's utterly unacceptable for a backbone provider to
> force their customers to use their cache.  I do, however, wish that
> more backbone providers would provide caching services to those people
> what want the service.

Most backbone providers run Squid in their datacenters and/or POPs and
offer to do ICP with any customer who wants it.  I don't like ICP -- see
http://www.vix.com/ietf/htcp.txt for the protocol I proposed to replace
it.  But the model is sound, and I would like to see more backbone
providers doing this.

> So, If someone is using site exec, etc in their code, and their
> provider/webmaster/mother didn't set up Progma: nocache, they're
> effectively screwed...erm...cached, right?  

No.

> Fantastic.  So, lets say I'm Joe Banner Advertizer.  Company X has paid me
> present their banner.  They wanted to limit the amount of money they spent
> so, they had me code my servers to only display their banner X times per
> day since I bill them on impressions.  Backbone provider Z installs one of
> your boxes.  By default, no matter how many connections on the limited..
> ..erm.. client side of the box are initiated to retrieve a "fresh"
> banner from our banner-farm, you send them Company X until the cache
> times out.

No.  For now, use freshness lifetimes (including pre-expiry for banners) and
correctly behaving caches will at worst do a GET/If-Modified-Since whenever
they are considering reusing the element -- so your origin server can count
the hits and can control when the object can no longer be reused.  The HTTP
standard already supports this.  It costs a TCP transaction per reuse, but it
avoids the actual transmission of the banner ad whenever reuse is correct.

In the near future, we'll see a different reuse model, based on RFC 2227:

    rfc2227.txt -- Simple Hit-Metering and Usage-Limiting for HTTP.
	J. Mogul, P. Leach. October 1997.
	(Format: TXT=85127 bytes) (Status: PROPOSED STANDARD) 

And again, the advertisers will be in full control, the standards will get
followed, and the backbone will have more bits free for Internet Telephony.
-- 
Paul Vixie
La Honda, CA			"Many NANOG members have been around
<paul at vix.com>			 longer than most." --Jim Fleming
pacbell!vixie!paul		 (An H.323 GateKeeper for the IPv8 Network)