Subject: [AAA-WG]: ISSUE: Specify Statefulness/Statelessness Requirements

From: "Bob Kopacz" <[email-masked]>
Date: Fri, 26 Oct 2001 12:49:04 -0400

Submitter name: Bob Kopacz
Submitter email address: [email-masked]
Date first submitted: October 26,2001
Reference: None
Document: draft-ietf-aaa-diameter-mobileip-08-alpha01
Comment type: T
Priority: 1
Section: 1, 1.2, 1.4
Rationale/Explanation of issue:

   The Mobile-IP Diameter draft is fuzzy regarding
   statefulness/statelessness requirements.  Implementers are left to infer
   the requirements.  Some people have inferred that an AAA home server must
   maintain session state, others have not made that inference.  

Requested change: 

   Specify the statefulness/statelessness requirements.

   If it is true that maintaining session-state is not required, then amend
   the draft as follows:

1. Up front, somewhere in the "Introduction" section, add the following
   text:

   "A AAA home server which supports the Mobile-IP authentication
   application MAY maintain session-state or MAY be session-stateless.  A
   AAA foreign server which supports the Mobile-IP authentication
   application MAY maintain session-state or MAY be session-stateless.  AAA
   redirect agents and AAA relay agents MUST not maintain session-state.
   AAA home and foreign servers, as well as AAA proxies and relays, MUST
   maintain transaction state."

2. 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."

   Remove the 2nd sentence, which begins "Of course ...".

3. 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."

   Remove the phrase "For new sessions" from the first sentence, so that
   the text reads:

   "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."

4  Section 1.4 "Allocation of Home Agent in Foreign Network", says"

   "Figure 7 shows the message flows for a Mobile Node requesting to keep
   the Home Agent assigned in Foreign network 1 when it moves to foreign
   network 2. [...].  If the Mobile Node was
   successfully authenticated the AAAH checks for the Origin-Host and
   the value of the Origin-Host of the previous request. If a AAAH
   deduces that the Mobile Node has moved to a new realm, it must check
   whether the Mobile can still use the previously assigned Home Agent."

   Change the sentence 
   
   "If the Mobile Node was successfully authenticated the AAAH checks for
   the Origin-Host and the value of the Origin-Host of the previous
   request." 
   
   to 
   
   "If the Mobile Node was successfully authenticated, a session-stateful
   AAAH checks for the Origin-Host and the value of the Origin-Host of the
   previous request."

   and add some text describing how a session-stateless AAAH server deduces
   that the Mobile Node has moved to a new foreign realm.