It really seems that HTTP based proxy services proxy more than just
HTTP. HTTP proxy services arent standardized on port 80. If
there is a 'defacto standard' I would say it is 8080, as coined
by Ari Luotonen, the original author of the CERN HTTPD Proxy.
Today, common practice is that this HTTP based proxy service
on port 8080 (or whatever an org chooses to configure their
clients with) does more than proxy HTTP. Most proxies
can proxy FTP, SSL via CONNECT, gopher, and some others.
If your behind a proxy and you FTP a file with a browser,
your speaking HTTP proxy 'protocol' from your client
to the proxy, and FTP from the proxy to the FTP server..
While Microsoft may use port 80, having been at other places,
its my impression that the standard proxy services are not 80,
but 8080.
This means nothing, however, the default port of IPP will not
affect its ability to go through proxies.
The http based "proxy service" should be considered its
own default port as well.
Given an IPP URI: http://myprinter.com:9999/printer5
Pretty much any proxy will pass this. The port that the
proxy is listening on is indicated in the proxy settings,
and is independent of the actual protocol destination.
The main place where trouble can be found I can
think of is when a filtering firewall (not proxy)
is used and it only allows traffic on port 80.
As time moves on, and more and more URLS refer
to other ports than 80, this type of firewall
IMHO has become less popular in favor of proxy
servers.
So, my beleif is that picking a new standard destination
port for IPP will make no difference in its ability
to be passed (and filtered) by proxy servers.
This is just the same as why picking a method other
than POST is also possible with todays proxies,
but thats another discussion.. :)
> -----Original Message-----
> From: Keith Moore [mailto:moore@cs.utk.edu]
> Sent: Friday, May 29, 1998 5:52 PM
> To: Paul Moore
> Cc: 'Keith Moore'; ipp@pwg.org; moore@cs.utk.edu
> Subject: Re: IPP> review of IPP documents
>
>
> You miss the point. The fact that people already have port 80 proxies
> installed doesn't matter. There's no way that we're going to
> standardize
> IPP on port 80 - HTTP already has that port, and IPP is a different
> service than HTTP.
>
> Once upon a time, a lot of people had email only access to
> the Internet.
> That wasn't an good reason for forcing every service to run
> over email.
>
> Keith
>