And, I think the big issue with the terminology is that 4244bis is application agnostic, so it is tagging what happens to the URIs (why/how the specific URI was overwritten). Whereas, specific applications can derive information, such as what "is" the real "target" for the request, from the History-Info header. So, IMHO, it's a matter of the target-uri document specifying that the last entry tagged by whatever name we come up with "is" the real "target" for the request. I believe it's up to the applications to describe how they make use of the History-Info and not for the History-Info to describe how applications can use it. History-Info purely reflects what happened from a SIP Protocol perspective and should not imply any application semantics. Indeed the intent of section 5 of 4244 was to inform the applications how they should decribe their usage of the header. Mary. Note: I changed the subject to hopefully make this topic easier to keep track of.
________________________________ From: Hans Erik van Elburg [mailto:[email protected]] Sent: Wednesday, March 11, 2009 3:59 AM To: Shida Schubert Cc: [email protected] List; Barnes, Mary (RICH2:AR00) Subject: Re: [Sip] Fwd: I-D ACTION:draft-rosenberg-sip-target-uri-delivery-01.txt One of the problems that made the discussion quite tedious is the complete inversed meaning of the terms "retarget" and "reroute" between 4244bis and target-uri factions have. Conclusion was that the terminology need to be properly defined and some attempt was made to start such activity. On 3. I have strong concerns when we start tagging the URI as to how they come about "retarget"/"mapped conficuration" etc. It is better to embellish them with a tag that just represents there meaning for example "istarget" or "hop". For the following reasons: 1. It is much more intuitive for the user of this information, its meaning can basically be guessed. 2. Such meaning also probably survives application in other problem spaces that we had not foreseen when introducing the concept. The solution that is described now in the target-URI delivery draft is not yet complete, it does not solve the freephone use case for example and in its current form it will deliver exactly the same target-URI as that which would be delivered by the P-Called-Party-ID header. Contrary to what the draft says. So some work is needed still. /Hans Erik van Elburg On Wed, Mar 11, 2009 at 7:13 AM, Shida Schubert <[email protected]> wrote: 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. Content-Type: text/plain<BR>Content-ID: <[email protected]><BR><BR> _______________________________________________ I-D-Announce mailing list [email protected] https://www.ietf.org/mailman/listinfo/i-d-announce Internet-Draft directories: http://www.ietf.org/shadow.html or ftp://ftp.ietf.org/ietf/1shadow-sites.txt _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [email protected] for questions on current sip Use [email protected] for new developments on the application of sip
_______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [email protected] for questions on current sip Use [email protected] for new developments on the application of sip
