Re: Review of draft-drage-sipping-service-identification-02

"DRAGE, Keith (Keith)" <drage@xxxxxxxxxxxxxxxxxx> · Mon, 23 Mar 2009 15:10:49 +0100

In my working copy I have added this to the string in front of the urn definition itself, rather than in 4.1. and 4.2. 

     Service-ID      = "urn:urn-7:" urn-service-id
     urn-service-id  = top-level *("." sub-service-id) 
     top-level       = let-dig [ *26let-dig ]
     sub-service-id  = let-dig [ *let-dig ]
     let-dig         = ALPHA / DIGIT / "-"

regards

Keith

________________________________

	From: Atle Monrad [mailto:atle.monrad@xxxxxxxxxxxx] 
	Sent: Tuesday, December 16, 2008 11:05 AM
	To: sipping; DRAGE, Keith (Keith)
	Cc: 3GPP_TSG_CT_WG1@xxxxxxxxxxxxx
	Subject: RE:  Review of draft-drage-sipping-service-identification-02

	I have some further comments to the draft that also would be useful to get on board in the next version.

	It is my understanding that the P-Preferred-Service and P-Asserted-Service headers shall contain the complete URN. This is also described in the introduction. However, in section 1 and in section 6 of the draft the P-P-S and the P-A-S headers has urn's like <urn-xxx:exampletelephony.version1>. To my understanding the complete urn shall be <urn:urn-xxx:exampletelephony.version1>. In section 6; note also the nit "example-telephony" (the dash shall be removed).

	I also assume that section 4.1 and 4.2 also needs to be updated to reflect that the complete URN shall be included in P-P-S and P-A-S headers. 

	3GPP assumes that the P-P-S and P-A-S headers shall contain the complete urn, thus it is necessary to align the draft.

	/atle

________________________________

	From: sipping-bounces@xxxxxxxx [mailto:sipping-bounces@xxxxxxxx] On Behalf Of Andrew Allen
	Sent: 24. november 2008 04:19
	To: sipping; DRAGE, Keith (Keith)
	Subject:  Review of draft-drage-sipping-service-identification-02

	I have reviewed draft-drage-sipping-service-identification-02

	Here are my comments

	--------------------------------------------------------------------------------------------------------------------------------------------------

	Abstract

	This URN can be used to identify services within the

	   SIP header fields defined in this document, and also within the

	   framework defined for caller preferences and callee capabilities in

	   to identify usage of both services and applications between end UAs.

	Proposed Rephrase

	This URN can be used within the SIP header fields defined in this document 

	to identify services, and also within the framework defined for caller 

	preferences and callee capabilities to identify usage of both services and 

	applications between end UAs.

	--------------------------------------------------------------------------------------------------------------------------------------------------

	1.	Introduction 

	   P-Asserted-Service: urn-xxx:exampletelephony.version1

	Add

	      Note to RFC editor: replace xxx with the assigned 3 numeric digit

	      Identifier

	--------------------------------------------------------------------------------------------------------------------------------------------------

	4.2.  The P-Preferred-Service Header

	   The P-Preferred-Service header field is used from a user agent to a

	   trusted proxy to carry the preferred service of the user sending the

	   SIP request that the user wishes to be used for the P-Asserted-

	   Service field value that the trusted element will insert.

	Proposed rewrite:

	   The P-Preferred-Service header field is used by a user agent 

	   sending the SIP request to provide a hint to a trusted proxy of the 

	   preferred service that the user wishes to be used for the P-Asserted-

	   Service field value that the trusted element will insert.

	--------------------------------------------------------------------------------------------------------------------------------------------------

	Propose add RFC 3840

	4.3.  Service and Application Definition

	   The service and subservice identifiers identify the service as

	   described in Section 1.  The URN may also be used to identify a

	   service or an application between end users for use within the

	   context of RFC 3841 [RFC3841] **and RFC 3840 [RFC3840]**.

	--------------------------------------------------------------------------------------------------------------------------------------------------

	Update Registration Information

	4.4 

	   Registration Information:  Registration version: 1; registration

	      date: 2007-04-21

	--------------------------------------------------------------------------------------------------------------------------------------------------

	5.1.1

	There is no text regarding the use of the P-Asserted-Service header by UACs.

	A UAC within the trust domain (such as a Media Gateway or Application Server) 

	Can also include a P-Asserted-Service header. This behavior should also be 

	documented in 5.1.1

	Proposed text

	A UAC that is within the same trust domain as the proxy it sends a request

	to, (e.g a Media Gateway or Application Server) MAY insert a 

	P-Asserted-Service header in a request that creates a dialog, or a request 

	outside of a dialog. This information MUST NOT conflict with other SIP

	or SDP information included in the request.  Furthermore, the SIP or

	SDP information needed to signal functionality of this service MUST

	be present.  

	--------------------------------------------------------------------------------------------------------------------------------------------------

	5.1.2

	There is no text regarding the use of the P-Preferred-Service header by proxies. This needs to be added.

	Proposed text

	When a proxy receives a request containing a P-Preferred-Service header the

	Proxy MAY use the contents of that header to assist in determining the service

	to be included in a P-Asserted-Service header field, (for instance to prioritize the

	order of comparison of filter criteria for potential services that the request could

	match). The proxy MUST NOT use the contents of the P-Preferred-Service header to

	identify the service without first checking against the capabilities (e.g.  SDP) contained in 

	the request. If the proxy inserts a P-Asserted-Service header in the request the proxy 

	MUST remove the P-Preferred-Service header before forwarding the request, otherwise the 

	Proxy SHOULD include the P-Preferred-Service header when forwarding the request.

	--------------------------------------------------------------------------------------------------------------------------------------------------

	6 Examples

	The text in 6 seems to originate from RFC 3325 and not modified as it seems to relate to P-Asserted-Identity and not P-Asserted-Service

	   In this example, proxy.example.com creates a P-Asserted-Service

	   header field from the user identity it discovered from SIP Digest

	   authentication, and the list of services appropriate to that user,

	   and the services that correspond to the SDP information included in

	   the request.  It forwards this information to a trusted proxy which

	   forwards it to a trusted gateway.  Note that these examples consist

	   of partial SIP messages that illustrate only those headers relevant

	   to the authenticated identity problem.

	The examples themselves seem identity related too with 407 Proxy Authorization which is not related to the functionality in this draft.

	Since SDP is the most likely means to determine the service I think this should be shown in the examples

	Probably two examples are needed one with P-Preferred-Service and one without. Also I think we should have in one of the examples the  

	proxy stripping the P-Asserted-Service header at the edge of the trust domain,

	Andrew Allen

	Manager Standards

	Research In Motion Ltd

	Office +1 847-793-0861 x20824

	BlackBerry Mobile +1 847 809 8636

	http://www.rim.com/ <http://www.rim.com/> 

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