Re: [sipcore] Feature-tags in the Path header field
Christer Holmberg <christer.holmberg@ericsson.com> Fri, 17 September 2010 15:39 UTC
Return-Path: <christer.holmberg@ericsson.com>
X-Original-To: sipcore@core3.amsl.com
Delivered-To: sipcore@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 011163A63CB for <sipcore@core3.amsl.com>; Fri, 17 Sep 2010 08:39:50 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.714
X-Spam-Level:
X-Spam-Status: No, score=-5.714 tagged_above=-999 required=5 tests=[AWL=0.885, BAYES_00=-2.599, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 2mtI+QSrS+Ki for <sipcore@core3.amsl.com>; Fri, 17 Sep 2010 08:39:48 -0700 (PDT)
Received: from mailgw10.se.ericsson.net (mailgw10.se.ericsson.net [193.180.251.61]) by core3.amsl.com (Postfix) with ESMTP id A243D3A67F7 for <sipcore@ietf.org>; Fri, 17 Sep 2010 08:39:47 -0700 (PDT)
X-AuditID: c1b4fb3d-b7cbeae00000772f-b4-4c938bdb34f8
Received: from esessmw0184.eemea.ericsson.se (Unknown_Domain [153.88.253.125]) by mailgw10.se.ericsson.net (Symantec Mail Security) with SMTP id B2.D5.30511.BDB839C4; Fri, 17 Sep 2010 17:40:11 +0200 (CEST)
Received: from ESESSCMS0356.eemea.ericsson.se ([169.254.1.78]) by esessmw0184.eemea.ericsson.se ([153.88.115.81]) with mapi; Fri, 17 Sep 2010 17:40:11 +0200
From: Christer Holmberg <christer.holmberg@ericsson.com>
To: Paul Kyzivat <pkyzivat@cisco.com>
Date: Fri, 17 Sep 2010 17:40:10 +0200
Thread-Topic: [sipcore] Feature-tags in the Path header field
Thread-Index: ActWbRvWE/vHRsJtRFKoEjfOlt+q+AAEA3tC
Message-ID: <7F2072F1E0DE894DA4B517B93C6A0585015BCA8B@ESESSCMS0356.eemea.ericsson.se>
References: <7F2072F1E0DE894DA4B517B93C6A058501703422@ESESSCMS0356.eemea.ericsson.se> <4C936714.2040808@cisco.com> <7F2072F1E0DE894DA4B517B93C6A058501703523@ESESSCMS0356.eemea.ericsson.se>, <4C936E79.3070906@cisco.com>
In-Reply-To: <4C936E79.3070906@cisco.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-Brightmail-Tracker: AAAAAA==
Cc: "sipcore@ietf.org" <sipcore@ietf.org>
Subject: Re: [sipcore] Feature-tags in the Path header field
X-BeenThere: sipcore@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: SIP Core Working Group <sipcore.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/sipcore>, <mailto:sipcore-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/sipcore>
List-Post: <mailto:sipcore@ietf.org>
List-Help: <mailto:sipcore-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/sipcore>, <mailto:sipcore-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 17 Sep 2010 15:39:50 -0000
Hi, >>>IIUC, you are asking if Path can be used with a new parameter >>>without any further standards action. Is that right? >> >>At this point I am asking about the usage of feature tags to indicate proxy features in general. > >Oh. I guess I missed the point. >But when feature tags are passed, it is as header parameters. >They have been explicitly defined to be allowed on Contact. >Every header is different in terms of what parameters it permits. Feature tags as such are not defined for Contact, or only for UA capabilities. RFC 3840 defines the feature-param parameter for Contact, A-C and R-C. RFC 4508 defines feature-param for Refer-To. So, if the idea of carrying feature tags in Path is ok as such, I guess one option would be an RFC which defines feature-param for Path (similar to what 4508 does for Refer-To). So, the extended Path ABNF may look something like: Path = "Path" HCOLON path-value *( COMMA path-value ) path-value = name-addr *( SEMI rr-param / feature-param ) (Assuming feature-param fits within the syntax for rr-param) >The fact that a parameter is defined for use on one header does not automatically usable with any other header. (Unless the two headers >share some common definition. For instance, if the definition of rr-param was extended for Route then I believe Path would automatically >pick that up as well.) I agree, and that's why I sent the e-mail to the list :) Regards, Christer > >> On 9/17/2010 7:17 AM, Christer Holmberg wrote: >>> Hi, >>> Introduction: >>> ----------------- >>> 3GPP is working on solution which improves the ability to >> be able to >>> move an ongoing IMS call from an IP based access network to >> a legacy >>> CS based network without dropping the call. >>> The solution requires a media anchoring proxy (called ATCF) in the >>> visited network, and a signaling anchoring application >> server (called >>> SCC AS) in the users home network. >>> Problem: >>> ------------ >>> The SCC AS, when it receives a REGISTER request from a UA, needs to >>> know whether there is a proxy with ATCF functionaltiy in the >>> registration path. The reason is that the SCC AS can then choose to >>> delegate session handover functionality to the ATCF, which provides >>> advantages related to voice interruption etc. >>> Possible solution: >>> ------------------------- >>> During registration the ATCF inserts a Path header field, so a >>> solution to indicate its support of the ATCF functionlaity >> would be to >>> insert a feature tag in the Path header field. >>> However, eventhough there is no syntax issue, the usage of feature >>> tags have only been specified for the Contact, Accept-Contact, >>> Reject-Contact and Refer-To header fields. >>> So, the question is whether there are any reasons why the >> proxy could >>> not use a feature tag in the Path header field for this. >> Entities that >>> don't support the feature will simply see it as an unsupported Path >>> header field parameter, and a registrar doing normal feature tag >>> matching shouldn't even look at the Path header field. And, >> based on >>> the feature tag definitions in RFC3840 and RFC2703, we >> don't think the >>> usage is necessarily limited to UAs Regards, Christer >>> >>> >>> >>> _______________________________________________ >>> sipcore mailing list >>> sipcore@ietf.org >>> https://www.ietf.org/mailman/listinfo/sipcore >>
- [sipcore] Feature-tags in the Path header field Christer Holmberg
- Re: [sipcore] Feature-tags in the Path header fie… Paul Kyzivat
- Re: [sipcore] Feature-tags in the Path header fie… Christer Holmberg
- Re: [sipcore] Feature-tags in the Path header fie… Paul Kyzivat
- Re: [sipcore] Feature-tags in the Path header fie… Christer Holmberg
- Re: [sipcore] Feature-tags in the Path header fie… Paul Kyzivat
- Re: [sipcore] Feature-tags in the Path header fie… Christer Holmberg
- Re: [sipcore] Feature-tags in the Path header fie… Paul Kyzivat
- Re: [sipcore] Feature-tags in the Path header fie… Christer Holmberg
- [sipcore] Draft new: draft-holmberg-sipcore-proxy… Christer Holmberg
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Paul Kyzivat
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Elwell, John
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Christer Holmberg
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Peter Musgrave
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Hadriel Kaplan
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Hadriel Kaplan
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Christer Holmberg
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Hadriel Kaplan
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Leis, Peter (NSN - DE/Munich)
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Christer Holmberg
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Leis, Peter (NSN - DE/Munich)
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… gao.yang2
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… DRAGE, Keith (Keith)
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… gao.yang2
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Andrew Allen
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Andrew Allen
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Dean Willis
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Dean Willis
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Christer Holmberg
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Dean Willis
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… R.Jesske
- Re: [sipcore] Draft new: draft-holmberg-sipcore-p… Christer Holmberg
- [sipcore] draft-holmberg-sipcore-proxy-feature- w… Cullen Jennings
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Paul Kyzivat
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Andrew Allen
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Christer Holmberg
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Hadriel Kaplan
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Shida Schubert
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Worley, Dale R (Dale)
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Leis, Peter (NSN - DE/Munich)
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… Christer Holmberg
- Re: [sipcore] draft-holmberg-sipcore-proxy-featur… hannu.hietalahti