User's Manual

CHAPTER 4. Message Flow
4-6
© SAMSUNG Electronics Co., Ltd.
During Authenticator Relocation
When the MS performs CSN-anchored Handover (HO) or the MS in Idle mode moves to
another ACR's area and performs location update, the following reauthentication procedure
is performed to move the authenticator from the existing serving ACR to the target ACR.
When the target ACR triggers the MS to perform the EAP authentication procedure again
with the AAA server and notifies the serving ACR of the authentication result, the
authenticator relocation procedure finishes.
Figure 4.3 Authentication Procedure (During Authenticator Relocation)
Category Description
(1)~(2) The T-ACR, which is the new authenticator, exchanges the Relocation Notify/Ack
message with the S-ACR, which is the previous authenticator, to relocate the
authenticator by performing the reauthentication procedure.
(3)~(11) The reauthentication procedure is performed in the target area in the same way as
the authentication procedure during initial entry.
When the Diameter protocol is used, the Diameter EAP Answer (DEA) message is
received from the AAA server. When the RADIUS protocol is used, the Access Accept
message is received from the AAA server.
(12)~(13) The RAS sends the T-ACR, which is the authenticator, the Key Change Confirm
message to indicate that the reauthentication procedure with the MS has finished.
(14)~(16) The T-ACR exchanges the Relocation Complete/Ack message with the S-ACR to
complete the authenticator relocation procedure.
(17)~(18) After authenticator relocation, the new authenticator notifies the anchor that the
authenticator has changed using the Context Rpt procedure.
MS T-RAS AAA T-ACR S-ACR
6) Diameter: DEA/RADIUS: Access Accept
4) PKMv2-RSP
8) PKMv2-RSP
3) AuthRelay EAP Transfer
11) SA-TEK handshake
7) AuthRelay EAP Transfer
9) Key Change Directive
10) Key Change Directive Ack
12) Key Change Confirm
13) Key Change Confirm Ack
5) Serving ASN triggers MS re-authentication with AAA Server
14) Relocation Complete_Req
15) Relocation Complete_Rsp
1) Relocation Notify
2) Relocation Notify Ack
17) Context_Rpt
18) Context_Ack
16) Relocation_Complete_Ack