Subject: RE: [AAA-WG]: digest issue 11 closure (fwd)

From: "Nelson, David" <[email-masked]>
Date: Thu, 7 Apr 2005 11:30:25 -0400

John Loughney writes...

> What you are suggesting is
> that we should dumb-down Diameter SIP so that it can live
> with RADIUS.  However, I don't think we have a requirement for
> this.

Well, the RADEXT WG *does* have a requirement that RADIUS extensions be
interoperable with Diameter.  I guess what you're saying is that the AAA
WG does *not* have a requirement that Diameter be interoperable with
RADIUS extensions.

There are two SIP Digest Authentication protocols, one in Diameter and
one in RADIUS.  My understanding is that one originated in 3GPP and the
other originated in 3GPP2.  Are you suggesting that these are disjoint
solution sets that need not interoperate?

---

From: Bernard Aboba <[email-masked]>
Date: Thu, 7 Apr 2005 11:51:59 -0700 (PDT)

> WG does *not* have a requirement that Diameter be interoperable with

The original idea was for Diameter to offer a superset of RADIUS
functionality, so that it would be possible to install Diameter agents and
servers in a network with RADIUS-capable NAS devices.   This was thought
to be important because common NAS devices do not today support Diameter,
and may not do so for a long time.

At the same time, Diameter needed to be able to offer functionality such
as improved transport and new applications that could not be built on top
of RADIUS.  Since RADIUS could not provide some of those features,
interoperability was not required for those elements (such as failover,
and Credit Control).

> solution sets that need not interoperate?

As far as I can see SIP Digest authentication does not require use of
features uniquely available in Diameter.  Since this is a new application,
one might posit that deployments will largely focus on Diameter rather
than RADIUS, but that is a hypothesis which could be wrong.  If in fact
RADIUS Digest becomes popular, then it may become necessary to gateway
RADIUS Digest to Diameter SIP, and without interoperability that could be
hard.   Why tempt fate?