Re: [BLISS] draft-ietf-bliss-shared-appearances: Provisioningconsiderations

["Francois Audet" <audet at nortel.com>]

Hi Andrew,

That's what I was thinking too for the two fields of importance here,
i.e., the To and the From.

I will point out that the Contact is completely up to the UA to 
decide (as long as it routes).

Specifically, in this case, Bob could use:
Contact: <sip:bob at bobpc.example.com>  

Or even:
Contact: <sip:kasrhs88354kakadhfg at bobpc.example.com>

Or
Contact: <sip:HelpDesk at bobpc.example.com;token=bob>

...you get the idea.

The reason why you may need to use something else than
HelpDesk as the contact is for cases where you need
to associate the signalling to a specific user.

For example, many phones allow for multiple 
users to be logged in simultaneaously (i.e., 
multiple accounts).

Think of a phone, for example, that happens to have
both Alice and Bob logged in on the same phone, and each
one having a shared appearance of HelpDesk./



> -----Original Message-----
> From: Hutton, Andrew [mailto:andrew.hutton at siemens-enterprise.com] 
> Sent: Wednesday, July 15, 2009 03:54
> To: Audet, Francois (SC100:3055); Alan Johnston
> Cc: bliss at ietf.org
> Subject: RE: [BLISS] draft-ietf-bliss-shared-appearances: 
> Provisioningconsiderations
> 
> 
> Indeed this getting interesting.
> 
> In version -02 the REGISTER in section 10.1 showed a normal 
> 1st party registration by alice but -03 shows a third party 
> registration which is a significant change.
> 
> I must admit I missed the text in -02 which stated "Bob and 
> Alice are in an appearance group identified by Alice's AOR. 
> Bob REGISTERs using contact sip:bob at ua2.example.com" and I 
> should have commented on that earlier.
> 
> As the draft is about sharing appearances of a single AOR 
> then surely third party registration is not necessary as it 
> could be that there is simply two helpdesk phones using a 
> single AOR and there is no "alice" or "bob" AOR's. So in the 
> simplest case the REGISTER would be:
> 
>    REGISTER sip:registrar.example.com SIP/2.0
>    Via: SIP/2.0/UDP ua1.example.com;branch=z9hG4bK527b54da8ACC7B09
>    From: <sip:HelpDesk at example.com>;tag=CDF9A668-909E2BDD
>    To: <sip:HelpDesk at example.com>
>    CSeq: 2 REGISTER
>    Call-ID: d3281184-518783de-cc23d6bb
>    Contact: <sip:HelpDesk at ua1.example.com>
> 
> Regards
> Andy
>  
> 
> >-----Original Message-----
> >From: bliss-bounces at ietf.org [mailto:bliss-bounces at ietf.org] 
> On Behalf 
> >Of Francois Audet
> >Sent: 14 July 2009 23:30
> >To: Alan Johnston
> >Cc: bliss at ietf.org
> >Subject: [BLISS] draft-ietf-bliss-shared-appearances: 
> >Provisioningconsiderations
> >
> >
> >> > Section 9:
> >> >
> >> > Delete first paragraph.
> >> >
> >> > Clarify the UA also REGISTERs to the AOR. Discuss the
> >> security implications, i.e.,
> >> > you either use the same shared username/password, or you
> >> use a different username/password
> >> > for HTTP digest, per user. Perhaps the security
> >> considerations can be described in section 15.
> >> >
> >> >   
> >> 
> >> I added text about authorization for third party registrations and 
> >> publication.  A little more text on this would be helpful.
> >
> >Ah-ah... Now we are getting down to business.
> >
> >I am now looking at new section 10.1 on registration, and I see that 
> >you are using indeed third-party registration (with To=HelpDesk, 
> >From=Alice).
> >
> >So, this would be one way to to it.
> >
> >Another way would be to NOT use third-party registration at all. In 
> >other words, Alice would send a first party registration on 
> behalf of 
> >HelpDesk (ie.., To=HelpDesk, From=Alice).
> >
> >Wouldn't that work?
> >
> >Then there is the whole issue of authentication with HTTP-Digest.
> >I guess one could use username="HelpDesk". In this case, the idea is 
> >that Alice would need to know the credentials for HelpDesk.
> >Another way would be to use username="alice" instead (i.e., her own 
> >credentials).
> >The decisions on which authentication you use would depend 
> on need of 
> >the administrator.
> >
> >Have you tought about this? Am I off based?
> >_______________________________________________
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> >BLISS at ietf.org
> >https://www.ietf.org/mailman/listinfo/bliss
> >
>