Moby Dick Consolidated System Integration Plan

D0103v1.doc Version 1 6.7.2003
The URP is triggered by the MTNM to send a Mobile Node Authentication Request (MNARq) when one
or more then one of the following events are detected:
• the current AAA state was lost due to: (re)booting, crashing, etc.
• expiration of authorization lifetime
• the AAA domain is changed because of an hand-over (inter domain HO)
At the time of registration the URP sends the Mobile Node Authentication Request message (MNARq) to
the attendant on the access router. The information contained in an MNARq is local/internal i.e. residing
in an configuration file on the MN e.g. NAI.
Other information that is used by URP is some external information e.g. the challenge taken from a
Router (Attendant) Advertisement. This information is added into the MNARq to avoid reply attacks.
The attendant responds to MNARq with MNARp
The MN carries out the following actions upon receiving an MNARp:
• check that < AAAC.h-MAC > is correct using the SK[MN-AAAC.h]; if not drop the whole
message
• process the AAA Result-Code, HA-Result-Code
• set up timers for being able to tell when the session identified by the Session-Id is over
• set up SA the MN-Attendant SA (using key material in Att-DH-PV)
In case of errors (transport-mechanism-related, AAA-related, mobile-IPv6-related) an exponential backoff
approach for resending packets is used. As this method does not use too much resources (bandwidth)
for sending requests.
The information about the internal states / info related to MNARq / MNARp signalling must be made
available; especially to be able to generate the SAs.
The AVPs exchanged between the AAAC.h and the MN are always authenticated by computing an
HMAC-MD5 over them using SK[MN-AAAC.h]
4.5.2.2 Attendant
Attendant is a diameter specific module in the access router. The Attendant comprises a module of
software that implements the AAA signalling and a set of routing policies; some of these policies are set
up as a consequence of the AAA signalling.
Registration
protocoll
handler
ATTENDANT
AAAC protocol
handler
AAAC
Server
Mapper, Mediator, Event gen.
AAAC client
Attendant
log
Session
Status
Trigger,
remove
S.A.
Configure,
Meter data
Security
Manager
Metering
Figure 82: The attendant
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