Subject: RE: [AAA-WG]: Diameter redirect

From: "MORAND Lionel RD-CORE-ISS" <[email-masked]>
Date: Fri, 21 Jul 2006 01:38:59 +0200

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De : MORAND Lionel RD-CORE-ISS 
Envoyé : jeudi 20 juillet 2006 11:55
À : 'Paulo Rolo'; [email-masked]
Objet : RE: [AAA-WG]: Diameter redirect

Hi Paulo,
 
Over the 3GPP Cx interface, the Public-Identity AVP is optional for SAR because there are specific cases for which the presence of the User-Name AVP is enough (please refer to the 3GPP spec for further details).
So, it was decided not to mandate the presence of the Public-Identity AVP in the SAR with the following limitation: at least one of the identity types shall be present in the SAR i.e. either a Public-Identity AVP or a User-Name AVP (of course, both AVPs may be present in the command).
 
If at least one identity is present in the command, it is always possible to perform a user identity to HSS resolution, as either Public-Identity or User-Name can be used as SLF key entry to retrieve the correct HSS name.
 
Hope this helps!
 
Lionel
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De : [email-masked] [mailto:[email-masked]] De la part de Paulo Rolo
Envoyé : jeudi 20 juillet 2006 11:00
À : [email-masked]
Objet : [AAA-WG]: Diameter redirect

Hello,

We are currently developing a set of Diameter interfaces and some doubts have arise, concerning SLF usage.

On ETSI TS 123 228 (IP Multimedia Subsystem (IMS)) at section 5.8.1 (User identity to HSS resolution) it is suggested that a Public User Identity should be selected and used as input to SLF_QUERY, in order to resolve to the correct HSS name. 

Also at section 6.1.2 (S-CSCF registration/deregistration notification) of TS 129 228 (IP Multimedia (IM) Subsystem Cx and Dx Interfaces), it is suggested that if Routing Information is not available for SAR (S-CSCF registration/deregistration), it should be routed to next diameter node, for example SLF.  

The issue is that on TS 129 229 (Cx and Dx interfaces based on the Diameter protocol) at section 6.1.3 (Server-Assignment-Request (SAR) Command) the Public-Identity is presented as an optional attribute. If it is not present how should be SLF_QUERY performed? All the other messages (UAR, LIR, MAR) have Public-Identity as mandatory.

Thanks in advance,

Paulo Rolo

Network and Protocols Unit

Intelligent Networks Department

Portugal Telecom Inovação, S.A