attachment-0001
<br><font size=2 face="sans-serif">2b is OK but not necessary. The printer and the redirect location can have whatever private understanding they wish to determine how to concoct the redirect uri.<br>
---------------------------------------------- <br>
Harry Lewis <br>
IBM Printing Systems <br>
---------------------------------------------- </font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td>
<td><font size=1 face="sans-serif"><b>"Robert Herriot" <bob@herriot.com></b></font>
<br><font size=1 face="sans-serif">Sent by: owner-ipp@pwg.org</font>
<p><font size=1 face="sans-serif">08/01/2002 03:14 PM</font>
<td><font size=1 face="Arial"> </font>
<br><font size=1 face="sans-serif"> To: <ipp@pwg.org>, Dennis Carney/Boulder/IBM@IBMUS</font>
<br><font size=1 face="sans-serif"> cc: <hastings@cp10.es.xerox.com>, Harry Lewis/Boulder/IBM@IBMUS</font>
<br><font size=1 face="sans-serif"> Subject: Re: IPP> Re: Last Call comment to remove redirect URL and status code from IPPGET</font>
<br>
<br><font size=1 face="Arial"> </font></table>
<br>
<br><font size=2><tt>You raise valid points on this issue. It is best not to revisit closed<br>
issues so late in the process unless there is a bug. I think that the<br>
time-out issue is NOT a bug (details below), but there may be another issue<br>
that needs clarification (details at the end of this email).<br>
<br>
Some people have commented that the IPP redirection is lacking a time-out<br>
which HTTP does have. However, if I understand RFC 2616 correctly, a<br>
redirection URI is cached by the client only when a Cache-Control or Expires<br>
header is present. So the default behavior is that a client does not cache a<br>
redirection URI. We could simply add language to ipp-get that redirection<br>
URIs SHOULD NOT be cached. An Expires attribute would make a better<br>
solution, but since only IBM wants this feature, we should keep the solution<br>
simple and not change past agreements.<br>
<br>
Now that Harry has said that he plans to support this feature, he removes my<br>
claim about the feature having no value to anyone. If we keep this feature<br>
then we should leave the ipp-get document unchanged except for the<br>
clarification that I suggested in the previous paragraph and the one I<br>
suggest in the next paragraph.<br>
<br>
Now for the other issue with redirection. The Get-Notifications operations<br>
has a printer-uri argument. What is its value for the Get-Notifications<br>
operation to the redirected URI. The ipp-get document is silent on this<br>
issue. Also how does the redirected server know what printer the<br>
subscription-ids apply to? There are two possible solutions.<br>
<br>
1) The printer-uri attribute's value is the original printer URI that<br>
responded with the redirection URI. This value tells the redirected server<br>
what printer the subscription-id belong to.<br>
<br>
2) The printer-uri attribute's value is the redirection URI (of the<br>
redirected server). In this case either<br>
<br>
2a) the subscription-ids must be unique across all printers served by the<br>
redirected server or<br>
<br>
2b) the redirection URI must encode the name of the original printer in its<br>
URI.<br>
<br>
Solution 2b fits in best with the existing architecture.<br>
<br>
Bob Herriot<br>
<br>
<br>
<br>
<br>
<br>
----- Original Message -----<br>
From: "Dennis Carney" <dcarney@us.ibm.com><br>
To: <ipp@pwg.org><br>
Cc: <hastings@cp10.es.xerox.com>; "Harry Lewis" <harryl@us.ibm.com><br>
Sent: Thursday, August 01, 2002 8:20 AM<br>
Subject: IPP> Re: Last Call comment to remove redirect URL and status code<br>
from IPPGET<br>
<br>
<br>
> At the risk of looking like I'm simply taking Harry's side since he and I<br>
> work together, I'm going to comment nonetheless.<br>
><br>
> This process *does* seem a bit arbitrary to me. I could probably go back<br>
> through (well, maybe not me, but I'm sure Tom could ;-) any document the<br>
> PWG has produced looking for things that "don't look right". Then I could<br>
> bring them up, and possibly get significant support in their<br>
> "not-looking-right-ness". However, in theory, whatever it is I'm bringing<br>
> up has already been discussed and decided upon in the past, by a number of<br>
> people who had their heads clearly focused on the task at hand, unlike<br>
now,<br>
> where probably fewer people are paying attention, and even those people<br>
> might not have really had their minds focused on the subject for months<br>
> (years?).<br>
><br>
> I think if a "problem" is discovered in a document, it should be brought<br>
> up, as Tom did. However, even if only one person pipes up to explain why<br>
> it is not a problem (it's a feature! :-), I would think the conversation<br>
> should end there--a conscious decision was made on the subject and opening<br>
> up documents to continual re-editing would seem to be a bad precedent.<br>
><br>
> If there is real consensus that this redirect mechanism is a "problem",<br>
> sure, let's consider getting rid of it. But if the consensus is simply<br>
> that we're not sure whether anyone is going to use it, I believe we must<br>
> have more useful things to do with our time than debate this.<br>
><br>
> Just my 2 cents worth...<br>
><br>
> Dennis Carney<br>
> IBM Printing Systems<br>
><br>
><br>
><br>
><br>
<br>
<br>
</tt></font>
<br>