Subject: [AAA-WG]: Question re: draft-mobileip-07 / Maintaining session-state by AAAH

From: "Bob Kopacz" <[email-masked]>
Date: Thu, 27 Sep 2001 08:31:09 -0400

Hi,

Is it a requirement that an AAAH, which supports the Mobile-IP application,
maintain session state, or can the AAAH be session stateless?

The draft doesn't explicitly say that session state is required, and some
sections of the draft suggest that the AAAH may be session stateless.

For example,

1. Section 1.6 "Diameter Session Termination", says "MAY": 

   "A Foreign and Home Agent following this specification MAY expect
   their respective Diameter servers to maintain session state
   information for each mobile node in their networks."

But other areas of draft-07, and some pending draft-08 changes, describe
some AAAH actions which seem to require session state.  For example...

1. Section 1.2 "Inter-Domain Mobile IP", says:

   "During the creation of the HAR, the AAAH MUST use a different session
   identifier than the one used in the AMR/AMA (see figure 2). Of
   course, the AAAH MUST use the same session identifier for all HARs
   initiated on behalf of a given mobile node's session."

2. Section 1.2 "Inter-Domain Mobile IP", also says:

   "For _new_ sessions, the AAAH MUST create an accounting session
   identifier, which is added to the Accounting-Multi-Session-Id AVP in
   the HAR message sent to the home agent."

3. Diameter Issue#110 proposes that an AAAH determine if the mobile node
has moved to a new domain by comparing the Origin-Realm of
the current AMR against the Origin-Realm of the previous request

Bob K.