Subject: Re: IPP>PRO - Print by reference

From: Roger K Debry <[email-masked]>
Date: Fri, 30 May 1997 09:00:50 -0400

So far we have said (rightly or wrongly) that the actual fetch
of the actual fetch of the referenced document was outside the
scope of IPP.  For example, an implementation might use FTP
to retrieve a document.  If this were the case, then don't we still
get by with just an origin server?   Do you thinnk we need to add
the fetch to IPP and use HTTP for this?

Roger K deBry
Senior Techncial Staff Member
Architecture and Technology
IBM Printing Systems
email: [email-masked]
phone: 1-303-924-4080

---------------------- Forwarded by Roger K Debry/Boulder/IBM on 05/30/97 06:52
AM ---------------------------

        ipp-owner @ pwg.org
        05/30/97 06:55 AM
Please respond to [email-masked] @ internet

To: jkm @ underscore.com @ internet
cc: ipp @ pwg.org @ internet
Subject: Re: IPP>PRO - Print by reference

>>>>> "JK" == JK Martin <[email-masked]> writes:

JK> We also readily agree with Roger's belief that print-by-reference
JK> should be considered a basic (ie, mandatory) requirement for IPP.

  One objection that was raised to the use of HTTP as a 'transport'
  was that it might require substantial complexity.  In response, I
  among others pointed out that only the 'origin server' requirements
  of HTTP would apply.  If print-by-reference is a MUST, then most of
  the HTTP client requirements would be equally applicable.

  As I said before, I believe that specifying how this works if
  present is a very good idea, but I believe that whether or not to
  put this feature in any given product should be a choice left to the
  vendor.

  This strikes me as an easy feature to describe as a very small set
  of attributes which describe whether or not print-by-reference is
  supported and if so what identity the printer is configured to use
  and any network access restrictions it may have.

--
Scott Lawrence           EmWeb Embedded Server       <[email-masked]>
Agranat Systems, Inc.        Engineering            http://www.agranat.com/

---

From: JK Martin <[email-masked]>
Date: Fri, 30 May 1997 13:49:39 -0400 (EDT)

Good point about passing credentials (or lack thereof) to the printer
for print-by-reference.

What if we were to implicitly limit print-by-reference to only world-
readable documents (ie, no credentials needed)?

For the suggested scenarios of enterprise document repositories and
general public repositories (eg, IETF drafts), this should work just
fine, right?  In the case of the enterprise, the repository is assumed
to be inside the firewall, anyway, so "public" access is pretty much
assumed.

	...jay

----- Begin Included Message -----

>From [email-masked] Fri May 30 13:28 EDT 1997
Date: Fri, 30 May 1997 09:57:10 PDT
From: Larry Masinter <[email-masked]>
Organization: Xerox PARC
To: Scott Lawrence <[email-masked]>
CC: JK Martin <[email-masked]>, [email-masked]
Subject: Re: IPP>PRO - Print by reference
Content-Transfer-Encoding: 7bit

The capability of being able to print-by-reference might
be thought of as similar to the capability to be able to
print any given media type. In fact, print-by-reference
might be implemented by sending, instead of
application/vnd.adobe.postscript or application/vnd.hp.pcl,
sending message/external-body.
>   and any network access restrictions it may have.

The difficult issue in print-by-reference is how the sender
supplies the credentials if any at all are required. There
is no single standard for identity in Internet protocols, and
there's no standard encapsulation of credentials.

Larry
-- 
http://www.parc.xerox.com/masinter

----- End Included Message -----

---

From: Scott Isaacson <[email-masked]>
Date: Fri, 30 May 1997 12:57:52 -0600

I thought that a "reference" in "print-by-reference" meant a URI.

If it is a URI, then the URI determines the method for "fetching".  We
do not need to do anything to IPP to define a new way to fetch.
If it is an HTTP URI, do a GET on the URL
If it is an FTP URI, use FTP, etc.

I don't see an URI like "ipp://..." being used.

I had thought about what Scott L. was suggesting about having an
attribute describe the whether the Printer supported print-by-reference
or not.  What if we made this like "notification-addresses-supported" which
is a list of URI schemes that are supported by the Printer.?

Scott

************************************************************
Scott A. Isaacson
Print Services Consulting Engineer
Novell Inc., 122 E 1700 S, Provo, UT 84606
V: (801) 861-7366, (800) 453-1267 x17366
F: (801) 861-4025, E: [email-masked]
W: http://www.novell.com
************************************************************

>>> Roger K Debry <[email-masked]> 05/30 7:00 AM >>>

Roger K deBry

---------------------- Forwarded by Roger K Debry/Boulder/IBM on 05/30/97
06:52
AM ---------------------------

        ipp-owner @ pwg.org
        05/30/97 06:55 AM

---

From: Scott Isaacson <[email-masked]>
Date: Fri, 30 May 1997 13:06:23 -0600

>>> JK Martin <[email-masked]> 05/30 11:49 AM >>>

I agree with this simplification.  In Austin, I thought we all agreed that
print-by-reference would only include "public" documents.  Yes, we all know
that
that doesn't allow all end users to print all documents that they can get at
through a browser, but it does allow for MANY end users to print MANY of the
documents that they can get at without any sort of authentication.

Let's not throw out a VERY useful feature, just because it does not solve
ALL problems EVERYWHERE.

Scott