Subject: [AAA-WG]: Issue 53: What if the AAAL cannot reach the HA

From: Pat Calhoun <[email-masked]>
Date: Tue, 12 Jun 2001 07:10:51 -0700

All,

I find the description of this particular issue somewhat misleading. I believe 
what is being requested here is the ability to NOT tie MIP so closely to
Diameter, right?

Here's what I mean. Currently the Diameter AMR includes the Registration Request,
which is forwarded to the Home Agent in the HAR. The Home agent processes the
embedded registration request, and replies with an HAA that includes the Registration
Reply, and so on.

What I believe this issue is asking for is the ability for the AMR to authenticate
and authorize the user, and reply with an AMA. At that point, the FA can issue the
Registration Request directly to the Home Agent. Of course, the reason why we had
decided against this proposed in the beginning was because we wanted to reduce the
number of round trips required to gain service, but there seems to be cases where
this functionality is valuable.

So, what I'd like to propose is a new success result code:

DIAMETER_LIMITED_SUCCESS
   When returned, the request was successfully completed, but additional
   processing is required by the application in order to provide service
   to the user.

and then in the Mobile IP application, we could add/change:

An AMA message with the Result-Code AVP set to DIAMETER_SUCCESS MUST
include the MIP-Home-Agent-Address, MIP-Home-Mobile-Node-Address
and MIP-Reg-Reply AVPs. The MIP-Home-Agent-Address AVP contains
the Home Agent assigned to the Mobile Node, while the MIP-Mobile-Node-Address
AVP contains the home address that was assigned.

An AMA message with the Result-Code AVP set to DIAMETER_LIMITED_SUCCESS
MAY include the MIP-Home-Agent-Address AVP if a dynamically assigned home 
agent was requested by the mobile node. Upon receipt of this result
code, the foreign agent MUST issue the Registration Request to the Home
Agent in the manner described in [4].

Would this work?

PatC

---

From: [email-masked]
Date: Wed, 13 Jun 2001 18:09:47 +0300

> this functionality is valuable.

Pat,

You are right - this is exactly the behaviour I was
asking for with this issue. 

I believe the solution you proposed in your e-mail would work.
It sure is good to have some explicit way of indicating that 
the FA needs to forward the request to the HA (such as the new 
result code you're proposing), rather than just deducing this 
based on the absence of the MIP-Reg-Reply AVP.

Thanks,
Henry