Re: : ISSUE, SIP, Duplicate user-name

The need to have a duplication is to have a smooth and easy transition 
from RADIUS to Diameter, because the RADIUS document already specifies 
Digest-Username.

Adding an AVP for consistency and smooth transition is considered more 
elegant than trying to save a few bytes here. As far as I know, we don't 
have any requirement that puts constraints on the number of bytes 
transferred.

/Miguel

[email protected] wrote:

> Hi!
> 
> I agree with everything you said about the usage of
> User-Name AVP.
> 
> But my issue was: why is there need for the Digest-Username AVP in
> the Diameter SIP Application? It is enough to have User-Name AVP.
> 
> When Digest is used the SIP-server fills User-Name AVP from the
> username contained in Authorization header.
> 
> When Digest is used the SIP-server fills Digest-Username AVP from
> the username contained in Authorization header.
> 
> Why is there need to transport this information once in
> the SIP-message, but twice in the Diameter message?
> It is redundant information.
> 
> Conclusion: Digest-Username AVP is not needed in
> Diameter SIP Application. Let's get rid of it.
> 
> 
> BR,
> Mikko
> 
> 
> 
>>-----Original Message-----
>>From: Miguel Garcia [mailto:[email protected]]
>>Sent: 27 October, 2005 13:32
>>To: Aittola Mikko (Nokia-NET/Tampere)
>>Cc: [email protected]
>>Subject: Re: [AAA-WG]: ISSUE, SIP, Duplicate user-name
>>
>>
>>This issue was discussed in the past and agreed as it is 
>>today. The main 
>>point is that Digest-Username assumes that you are using Digest 
>>authentication and there is a username already present in the Digest 
>>information. However, we may have other non-Digest authentication 
>>mechanisms in the future. In order to provide a smooth transition, we 
>>need to have a username in order to identify the user in the 
>>database, 
>>independent of the authentication mechanism.
>>
>>To be more explicit:
>>
>>User-Name is used for authorizing a registration and 
>>identifying a user 
>>data in a database, even when there is no digest authentication (and 
>>thus no Digest-Username AVP).
>>
>>Section 7.2 has procedures for the User-Name AVP:
>>
>>If a User-Name AVP is present in the Diameter UAR message, then the 
>>Diameter server MUST authorize that User-Name AVP value is able to 
>>register the SIP or SIPS URI included in the SIP-AOR AVP. If this 
>>authorization fails, the Diameter server must set the 
>>Result-Code AVP to 
>>DIAMETER_ERROR_IDENTITIES_DONT_MATCH and send it in a Diameter 
>>User-Authorization-Answer (UAA) message.
>>
>>         Correlation between User-Name and SIP-AOR AVP values is 
>>required in order to avoid registration of a SIP-AOR allocated to 
>>another user.
>>
>>
>>Then later in Section 7.7 the text reads:
>>
>>If the SIP request includes some sort of authentication 
>>information, the 
>>Diameter client MUST include the user name, extracted from the 
>>authentication information of the SIP request, in the 
>>User-Name AVP value.
>>
>>Note that the text is not Digest specific.
>>
>>
>>So I am afraid I can't agree with this issue.
>>
>>/Miguel
>>
>>[email protected] wrote:
>>
>>
>>>Description of issue: Duplicate user-name
>>>Submitter name: Mikko Aittola
>>>Submitter email address: [email protected]
>>>Date first submitted: 26 Oct 05
>>>Document: sip (v. 10)
>>>Comment type: T
>>>Priority: S
>>>Section: 8.5.4
>>>Rationale/Explanation of issue:
>>>
>>>SIP-Authorization grouped AVP contains required AVP
>>>Digest-Username. This is duplicate information with
>>>the User-Name AVP sent in the MAR-command.
>>>
>>>
>>>Rquested changes:
>>>
>>>Remove Digest-Username from SIP-Authorization AVP. If needed
>>>add text where it is explained that Digest-Username is translated
>>>to User-Name in the case of Radius-Diameter translation.
>>>
>>>
>>>BR,
>>>Mikko
>>>
>>
>>-- 
>>Miguel A. Garcia           tel:+358-50-4804586
>>sip:[email protected]
>>Nokia Research Center      Helsinki, Finland
>>
>>
> 
> 

-- 
Miguel A. Garcia           tel:+358-50-4804586
sip:[email protected]
Nokia Research Center      Helsinki, Finland