Gateways: was: URL routing

Tim Berners-Lee <>
Date: Thu, 8 Jul 93 15:31:10 +0200
From: Tim Berners-Lee <>
Message-id: <>
To: Markus Stumpf <>
Subject: Gateways:  was: URL routing
Status: RO

WWW clients can be set to redirect requests to a
gateway using

	setenv WWW_http_GATEWAY
	setenv WWW_wais_GATEWAY
	setenv WWW_gopher_GATEWAY
setting it separately for each type of URL.
They then use http to go to the gateway, which returns
whatever document/search it was they wanted.

The client can in fact run with a rule file instead of
the environment variables,
which allows more complicated selections to be set up.

The CERN WWW server (httpd) will run as a gateway
just by being configured correctly. The config
file needs lines like for example

	pass	http:*
	pass	wais:*
	pass	gopher:*
	fail	news:alt.*
	pass	news:*

The gateway can at the same time be a server
for files, by putting in lines like

	pass*	file:/pub/*
	pass	/*			file:/pub/*

There are lots of alternatives.	
It all comes out in the wash if the system is
sufficiently modular in the first place.

	Tim BL

Begin forwarded message:

Subject: URLs and "routing" information
From: Markus Stumpf <>
Date: 	Wed, 7 Jul 1993 14:41:55 +0200


We have a workstation cluster, where all the students of the first  
are put on. They have full email and USENET news access, but no  
services such as ftp, telnet, www, gopher, etc. (no default routes on
these machines) outside the campus net.

I have just taken a look at go4gw and I think the idea behind is
rather good.
As I understood it (it was a short look) it rewrites the addresses of
the gopher objects, so that the host is always the gateway server and
the real host becomes part of the object-path.

I think it would be a good idea to have this kind of routing in URLs,  
It would then be rather simple to write gateway servers to other
services which may not be accessible directly or to write servers to  
on firewalls.

Would this be possible?


 Markus Stumpf