Re: [sipcore] Draft new: draft-holmberg-sipcore-auth-id-00

[[e-mail] (Dale R. Worley)]

> From: Christer Holmberg <[e-mail]>

> The function is to provide the authorization server identity to the
> S-CSCF (registrar). The S-CSCF MAY use that information when
> authorizing a user. For example, it can check whether the
> authorization server is authorized to provide IMS credentials to the
> user.

When you say "provide the authorization server identity", so you mean
"provide the identity of the authorization server"?  And does that
mean that registrar/S-CSCF will use that as an input to its
authorization check (as basically a string, much like the username and
realm) or is it the DNS name of an authorization server that the
registrar is supposed to query to check the validity of the
credentials?

I think that you mean the former rather than the latter.

In that case, in what way does authorization-entity differ from the
username and realm?

> > I assume that you intend to extend the set of SIP authorization
> > models; it's necessary to describe, at least in outline, what the
> > new authorization model is and how "authorization-entity" is used
> > in it so people can tell whether they want to use it in their SIP
> > implementations and how they would do so.
> 
> The way the IMS core authorizes users as such is not changed. 

OK, but is the way that IMS core authorizes users different from the
usual SIP digest model?  If so, documenting that authorization method
could be useful for broader SIP usage.

> As always, we need to decide whether there is any interest for this
> outside 3GPP. But, I am happy to provide more
> information/clarification.

Granted.  But to determine that, people outside of 3GPP need to know
what the mechanism does, and that's not very clear yet.

Dale