RE: [Sip] Privacy statements and History (draft-ietf-sip-history-info-04.txt)

["PROUVOST Sebastien RD-CORE-ISS" <[e-mail]>]

Mary, Sebastien, Roland, 
 
I agree that we should let the possibility for a proxy not to remove the hi-entry even if privacy is requested and even if the request is forwarded to a Request-URI associated with a domain for which the proxy is not responsible (if there is an agreement between the domains that ensures the proxy that privacy will be applied to the request). 
I suggest a text that would look like (in case privacy is requested): "the hi-entry SHOULD be removed by the proxy unless it knows that it can rely on a downstream privacy service to apply the requested privacy ".
 
Sebastien.


________________________________

De : [e-mail] [mailto:[e-mail]] De la part de Mary Barnes
Envoyé : mercredi 10 novembre 2004 19:54
À : GARCIN Sebastien RD-CORE-ISS; Jesske, R; [e-mail]
Objet : RE: [Sip] Privacy statements and History (draft-ietf-sip-history-info-04.txt)



I still contend that the SHOULD is sufficient.  SHOULD means that in general processing, if the hi-entry has a privacy header, then the usual processing would be that it would be removed (i.e it was added for a specific reason and in general should be used to remove the entries based on well defined criteria).  If there are reasons, such as local policy, that would allow the forwarding in specific cases, then it's okay that it is forwarded.  I think the use of MAY results in less precision and I think the value and critera for associating and removing the privacy header with the hi-entry becomes much less clear.  

I'd like to hear more opinions on this topic, prior to agreeing to making the change (from the MUST to MAY rather than MUST to SHOULD). 

Regards, 
Mary 


-----Original Message----- 
From: GARCIN Sebastien RD-CORE-ISS [mailto:[e-mail]] 
Sent: Wednesday, November 10, 2004 12:28 PM 
To: Barnes, Mary [NGC:B601:EXCH]; Jesske, R; [e-mail] 
Cc: [e-mail] 
Subject: RE: [Sip] Privacy statements and History (draft-ietf-sip-history-info-04.txt) 


Mary and roland, 

Actually, the statement regarding the forwarding of hi-entries beyond the domain for which the proxy is responsible should rather be a matter of local policy and thus a MAY should be used instead of SHOULD. We are potentially dealing with network boundaries where agreements for forwarding such kind information can be reached. 

Section 4.3.3.1.1 
This section should be re-reworded in accordance with the statement above (I can provide some text is we can agree). 

Section 4.3.3.1 is ok (apologies for not being explicit) 

Best regards, 
sébastien 



________________________________ 

De : Mary Barnes [mailto:[e-mail]] 
Envoyé : mercredi 10 novembre 2004 16:21 
À : 'Jesske, R'; GARCIN Sebastien RD-CORE-ISS; [e-mail] 
Cc : [e-mail] 
Objet : RE: [Sip] Privacy statements and History (draft-ietf-sip-history-info-04.txt) 


Roland and Sebastien, 
  
I too agree with the proposal to change the strength of the referenced statement from section 4.3.3.1.1  from MUST to SHOULD. This change is consistent with the other normative statements in section 4.3.3.1.1, which are SHOULDs rather than MUSTs.   I'll make that change in the next rev unless someone raises concerns over that change. 


On the second concern, I'm not clear what the proposed change is for the following: 
[SG] Another issue is the decision to add hi-entries in a privacy context. A proxy changing the target (i.e. the proxy is responsible of the resource reflected in the received Request-URI) of a request which contained a "privacy=history" header MAY add a history-entries provided that it knows it can rely on other entities within the trust domain to apply the requested privacy. This affect item 4 in the list on conditions of section 4.3.3 and 4.3.3.1. 


Item 4 in section 4.3.3 describes the general situation, thus the strength (MAY) describes the general fact that the use of privacy is optional.  The normative text provided in 4.3.3.1, provides the general model for adding hi-entries, with the privacy specific considerations for adding the entries described in 4.3.3.1.1.  I think what you're suggesting is changing the strength of the following statement in section 4.3.3.1:

" The hi-entry MUST be added following any hi-entry received in the request being forwarded." 
I can see that in the context of privacy considerations, this might seem misleading.  That MUST was originally a SHOULD but was changed (as discussed on the list and at IETF-60) to MUST based on issue JRE- 4, so a simple change of MUST to MAY would not at all work.  I thought it was clear from the statement at the beginning of 4.3.3.1, that this section is describing the scenario under which the general privacy considerations had been evaluated and the intention was to add an hi-entry, thus the statements should be read in the context that the general screening indicates that an hi-entry SHOULD be added and if one is added it MUST be added following any entry that's already in the request to preserve the ordering.   If you have explicit changes to the text that you think would further clarify the functionality, we can discuss. 


Roland, if you have specific text on how I could incorporate a reference to RFC3323, we can consider that; fundamentally any discussion of privacy depends on RFC 3323, so it's not clear to me how you were suggesting we incorporate such a reference.  The text in this document (history-info) should accurately describe the processing impact of the new "history" priv-value. 


Thanks for your input, 
Mary 

                -----Original Message----- 
        From: Jesske, R [mailto:[e-mail]] 
        Sent: Wednesday, November 10, 2004 7:59 AM 
        To: [e-mail]; Barnes, Mary [NGC:B601:EXCH]; [e-mail] 
        Cc: [e-mail] 
        Subject: AW: [Sip] Privacy statements and History (draft-ietf-sip-history-info-04.txt) 
        
        
        Dear Mary and Sebastien, 
        here are my Comments to Sebastien's statements: 
         
        Your first proposal I can accept from my point of view. 
        On you second issue my impression is that this issue must be seen with regard to RFC3323 where privacy and the trust concept is described. Perhaps a reference to this document should be included.

        On your last point, I think we can also refer to RFC 3323. 
         
        What are you thinking? 
         
        Best Regards 
         
        Roland 
         

                 ---- Mary snipped forwarding info to keep message smaller-----------  
                
                                                                -----Original Message----- 
                                From: GARCIN Sebastien RD-CORE-ISS [mailto:[e-mail]] 
                                Sent: Monday, November 08, 2004 10:11 AM 
                                To: Barnes, Mary [NGC:B601:EXCH]; [e-mail] 
                                Subject: [Sip] Privacy statements and History (draft-ietf-sip-history-info-04.txt) 
                                
                                
                                Hi mary, all 
                                 
                                When reading draft-ietf-sip-history-info-04.txt, I have trouble in understanding some of the statements which relate to the forwarding rules for history-entries subject to privacy. It is an important requirement that History-entrie(s) with a Privacy=history, session, or header are indeed forwarded to entities which belong to the same trust domain. The removal of specific history-entries should only occur if the peer does not belong to the trust domain.

                                 
                                In the current text (section 4.3.3.1.1) : 
                                If a request is  being forwarded to a Request URI associated with a domain for which the proxy is not responsible and there is a Privacy header in the request with a priv-value of "session", "header" or "history", the proxy MUST remove any hi-entry(s) prior to forwarding. 

                                 
                                The current wording is misleading since it gives the impression (maybe intentionnal) that it is not possible to forward history-entries with Privacy statements to domains under the responsability of e.g. another operator belonging to the same trust domain.  

                                 
                                [MB]: Current wording is consistent with terminology in RFC 3261 in terms of describing who is able to change the Request URI in a specific request (based on section 16.5): 

                                   " A proxy MUST NOT add additional targets to the target set if the 
                                   Request-URI of the original request does not indicate a resource this 
                                   proxy is responsible for. 
                                
                                      A proxy can only change the Request-URI of a request during 
                                      forwarding if it is responsible for that URI. " 
                                Since History-Info (and associated privacy) are only added to the request, when an entity that is allowed to change the Request-URI retargets the request, it seemed sensible to use consistent wording to explain that.   

                                [/MB] 
                                 [SG] I have no problem with the statements above. My concern is that if there is a hi-entry already embedded in the request with a Privacy statement, then, it should be up to local policy to decide whether or not a proxy shall pass on those hi-entries to a trusted domain. The sentence in section 4.3.3.1.1 precludes this. I would propose to lighten the strenght of the sentence as follows:

                                 
                                If a request is  being forwarded to a Request URI associated with a domain for which the proxy is not responsible and there is a Privacy header in the request with a priv-value of "session", "header" or "history", the proxy MAY remove any hi-entry(s) prior to forwarding. 

                                 
                                [SG] Another issue is the decision to add hi-entries in a privacy context. A proxy changing the target (i.e. the proxy is responsible of the resource reflected in the received Request-URI) of a request which contained a "privacy=history" header MAY add a history-entries provided that it knows it can rely on other entities within the trust domain to apply the requested privacy. This affect item 4 in the list on conditions of section 4.3.3 and 4.3.3.1. 

                                 
                                The concept of "trust domain" should be used when discussing the forwarding rules pertaining to information subject to privacy. Furthermore, the requirement for forwarding history-entries to trusted entities should be stated more clearly in the draft. 

                                                                [MB]: The whole concept of what defines privacy in terms of the proxy's use of the privacy header is outside the scope of History-Info functionality and really a matter of local policy.   I think the functionality that you want is a matter of local implementation and policy in terms of operators establishing this "trust domain" model to which you refer.  History-Info defines the mechanism to ensure the privacy of the requests, but it doesn't explicitly define how the proxy knows whether it is responsible for that resource.    I don't think this is a matter of standardization.  I thought the use of the term "domain" rather than "resouce" would be helpful, but perhaps changing it to the more general "resource" would resolve this concern and/or a statement clarifying what I've just described should be added in the draft. 

                                [/MB] 
                                [SG]   Changing the term "domain" to "resource" does not solve the problem I mentionned above. In order to reflect current operator requirements, the draft should not PRECLUDE the fowarding of existing history information towards trusted domains.

                                 
                                Thank you for clarifying this point. 
                                 
                                Best regards, 
                                sébastien 
                                 
                                 

                                ------Remainder of non-related part of this thread has been deleted by Mary------------------

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