IPP Mail Archive: IPP> Re: Implications of introducing new scheme and port for existing HTTP servers

IPP> Re: Implications of introducing new scheme and port for existing HTTP servers

David W. Morris (dwm@xpasc.com)
Mon, 1 Jun 1998 19:34:06 -0700 (PDT)

I would strongly urge you to NOT introduce a new url scheme. I would
assert that any existing proxy which doesn't reject an unknown scheme
badly broken. At the very minimum, proxies would have to be configured
to accept this new scheme and interpret it as HTTP. A requirement which
will be fraught with failure in the implementation. I'm not aware of any
proxies which would be this simple to adapt so this is speculation of the
lower bound of difficulty generated by using a new scheme.

(I'm also not wild about new HTTP methods as I know of existing proxies
which will reject unknown methods. Don't know of any which will accept
unknown methods. I'm also unaware of any firewall software which examines
the HTTP request method as part of its algorithm but then I'm not a
firewall expert.)

A new default port may be OK but I believe unnecessary. In any case, an
installation should be allowed to overload port 80 etc. if desired by
over-riding the default if it isn't 80.

But then I don't buy the basic premis that its necessary to distinguish
between IPP (or any other HTTP-based content protocol) and HTTP.

Dave Morris

On Mon, 1 Jun 1998, Carl-Uno Manros wrote:

> Hi,
>
> As most of you know already, the Internet Printing Protocol (IPP) WG has
> suggested using HTTP as "transport", with the payload in the form of a MIME
> object passed with the POST method.
>
> As part of the onging IESG review process, the Application Area Director
> Keith Moore has suggested to distinguish IPP traffic from "normal" HTTP
> traffic by:
>
> 1) the introduction of a new scheme called "ipp"
> 2) the introduction a new default port number for IPP servers.
>
> Before the IPP WG responds to those suggestions, the IPP WG would like to
> get some advice from the HTTP WG on the implications of such a change.
> In particular, we want some feedback on how easy or difficult it would be
> to configure existing web servers to accomodate the suggested changes.
>
> Please note that many printer vendors are not in the business of developing
> web servers or HTTP servers and are dependent on getting those compoments
> from other vendors.
>
> Please respond back to the IPP DL at:
>
> ipp@pwg.org
>
> Thanks,
>
> Carl-Uno Manros
> Chair of the IETF IPP WG
>
>