I think there is another solution proposal that we should pursue for
issue 3 identified in the email summary sent by Shida earlier this week
- I've snipped all the text except for that issue and issue 2 in the
summary below.  I do think the discussion has confounded the two issues
and I think it ought to be clarified that if we agree to the two tags
per issue 3, that the options for the terminology MUST change. And,
perhaps this is why the other discussion threads aren't progressing
well.
 
So, Hans Erick, I would like clarification on as to your view on the
solution:
 
In general, ISTM that one of the issues we're having in this terminology
thread is that you are considering the solution to be that the
hi-entries are tagged as they 
are added to the request.  And, just for clarification from my
perspective, that is NOT the solution in either 4244bis or target-uri. 
 
I don't view it as a problem necessarily if you'd like to pursue an
alternate solution, we just need to be clear that's what you're
advocating. In that case, I would agree the "retarget" is not an
appropriate tag for the entries, as you don't know at the point in time
that you add an hi-entry that it will be retargeted. In the case of this
approach to the solution, you do have to alter the mechanism for
determining the hi-entry that your services would want to use. You would
need to skip the most recent/last hi-entry (as that would contain the
same as the Request-URI in the incoming request), since it would be
tagged if you use this solution approach. Thus, you'd have to take the
next hi-entry that you find that has the desired "tag".  I will posit
that we could accomplish this solution without any changes to 4244 by
just registering new SIP URI parameter(s).   And,  that's not to say we
shouldn't do a 4244bis as there are other issues to address in that
document, but that allows the target-uri to describe a solution that
makes use of 4244bis "as is".
 
So, feedback on this specific point (from Hans Erik and others) would be
appreciated. 
 
Mary.
 
 
 

________________________________

From: Shida Schubert [mailto:[email protected]] 
Sent: Wednesday, March 11, 2009 1:13 AM
To: [email protected] List
Cc: Barnes, Mary (RICH2:AR00)
Subject: Fwd: I-D ACTION:draft-rosenberg-sip-target-uri-delivery-01.txt 



We have submitted the updated target-uri draft based on the comments 
submitted to the list and comments received at IETF73. 

I have taken over as editor as Jonathan didn't have the cycles to 
update the draft, with Francois, Christer and Hans Erick as additional 
co-authors and great deal of help from Mary.  
 
The following summarizes the changes made to the target-uri document
1. Added use-case for toll-free number back
2. Added definition of "retarget" operation. 
3. Removed a reference to URN
4. Added a text discussing the difference to P-Called-Party-Id
5. Changed parameter name from "target" to "istarget"
 
Note, that the target-uri document still contains the normative text for
the
History-Info header.
 
In addition, Mary (with Francois as co-author) has submitted a
rfc4244bis, with the following changes:
1. Incorporated the normative aspects of the target-uri document
into the existing normative text in RFC 4244 - the functionality is 
virtually identical (as is some of the text) as the HI based solution 
described in the target-uri document.  It's important that the solution
be integrated into RFC 4244 as it MUST work and be based on the
normative
aspects of RFC 4244.
2.  Added the use cases from target-uri the the summary
in the overview of rfc4244bis.
3. Added an additional requirement to capture the "target-uri"
information.
4. Fixed an error in the RFC 4244 ABNF and added "retarget" parameter.
5. Added a more simplified example.
 
 
We had some very long offline exchanges as to the best way forward and
remaining work for both documents.
 
Some of the issues identified are:

::Issues::
   1. Should we remove the normative text from target-uri and progress
       4244bis along with the target-uri document to meet the chartered
      SIP WG milestone? 
 
 
   2. Name of the parameter. 
      At the last meeting, parameter "target" was said inappropriate 
      because voicemail-uri spec already defines a parameter called 
      "target" which also can be found in hi-entry, thus potentially 
      causing confusion.
     
      Currently the target-uri draft uses "istarget" and 4244bis uses
      "retarget"  but we could never come to 
      a consensus on what name is appropriate.  Other suggestions have
      included the following:
      "target-identity" (someone didn't like that "identity" is also a
SIP header)
      "reg-uri"  (can be paired with "mapped-uri" for item 3 below)
      "aor"
      "jibberish" 
      etc.
 
      One reason this is so difficult relates to the problem statement
in target-uri in that
      RFC 3261 doesn't differentiate the mechanism by which the new
      (target) Request-URI is selected.  Another issue is that some of
the terminology in
      RFC 3261 is overloaded - e.g., "forwarding" refers both to a Proxy
      which does not have responsibility for the domain of the
request-URI
      in the incoming request, thus the proxy just "forwards" the
request to
      the next hop AND "forwarding" is used to describe the process
whereby
      the outgoing request is built and "forwarded" to the next hop at
which
      point the proxy does not know how the new request-uri was
selected.
      RFC 4244 has attempted to clarify the terms and attempts to use
"forward" 
      in the context of the former situation and "retarget" for the case
whereby
      a proxy is responsible for the domain and thus can use a number of

      mechanism to select the new target for the request - e.g., a
REGISTRAR, 
      configured data, etc.  

 3.  Related to the last point in item 2 above, it has been proposed
that
      we differentiate the hi-entries even more by defining separate
parameters
     for registered and configured/mapped contacts. 
     Currently when the R-URI is translated to a URI which is either
derived 
     from location service lookup(registered by UA) or from mapping 
     table, there is no differentiation as to how the URI was derived
once it is
     added to the list of potential targets.
     
     The general consensus of the authors of the two documents was that
it may 
     be useful for some services to have the hi-entries tagged with the
     more specific information. 
 
     And, of course, this gets us into another naming contest. In the
end, the naming
     is not so important as long as the term isn't too overloaded and it
is defined
     precisely in the document(s).
 
We would appreciate WG feedback on these issues and any other comments
on
the two documents prior to IETF-74.
 
Regards,
Shida and Mary.



Begin forwarded message:

        From: [email protected]
        Date: March 10, 2009 2:30:01 AM JST
        To: [email protected]
        Subject: I-D
ACTION:draft-rosenberg-sip-target-uri-delivery-01.txt 
        Reply-To: [email protected]

        A New Internet-Draft is available from the on-line
Internet-Drafts 
        directories.
        
        
        Title : Delivery of Request-URI Targets to User Agents
        Author(s) : J. Rosenberg, H. van Elburg, C. Holmberg, F. Audet,
S. Schubert
        Filename : draft-rosenberg-sip-target-uri-delivery-01.txt
        Pages : 16
        Date : 2009-3-9
        
        When a Session Initiation Protocol (SIP) proxy receives a
request
          targeted at a URI identifying a user or resource it is
responsible
          for, the proxy translates the URI to a registered or
configured
          contact URI of an agent representing that user or resource.
In the
          process, the original URI is removed from the request.
Numerous use
          cases have arisen which require this information to be
delivered to
          the user agent.  This document describes these use cases and
defines
          an extension to the History-Info header field which allows it
to be
          used to support those cases.
        
        A URL for this Internet-Draft is:
        
http://www.ietf.org/internet-drafts/draft-rosenberg-sip-target-uri-deliv
ery-01.txt
        
        Internet-Drafts are also available by anonymous FTP at:
        ftp://ftp.ietf.org/internet-drafts/
        
        Below is the data which will enable a MIME compliant mail reader
        implementation to automatically retrieve the ASCII version of
the
        Internet-Draft.
        

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