Subject: [AAA-WG]: [AAA-WG] Some remarks on Session Mobility

From: <[email-masked]>
Date: Wed, 9 Apr 2003 18:24:38 +0800

Hi,
 
To help the "Diameter Session Mobility" draft is better recognized, some addtional information is provided here.

Requirement in Mobile Network AAA:
1. A localized AAA service for mobile nodes;
2. Handling real-time services' unsolicited messages (eg. STR) for roaming mobile nodes.
 
What we propose:
1. An hierarchy AAA service via the dynamic maintenance of Diameter User Session;
2. An anchor AAA server acts as secure proxy towards Mobile node's Home AAA server (work well with CMS application).
 
Why this approach?
1. Why local AAA servers are also involved?
    ARs can not maintain a passing-by MN's information for long time, and then we can not expect ARs forward messages hop by hop.
 
2. When Diameter User Session is updated?
    Under study. And "After handover" is recommended, if the handover is from a trusted AR.
 
3. Why roundtrips?
    This approach is helpful when the Mobile Node is far away from where it should be authenticated. Under such situation, this approach is time-effective.
 
4. Why information exchange between local AAA servers?
    It helps the Mobile Node being authenticated locally, and also helps the Diameter User Session is explicitly maintained within:
  (AAAH) - (Anchor AAA server) - (local AAA server) - (current AR)

Best regards,
roger