Cisco ASR 5000 Series - Page 443

Packet Data Interworking Function Overview
Sample Deployments ▀
Cisco ASR 5000 Series Product Overview ▄
OL-22938-02
Figure 121. Simple IP Fallback Message Sequence
Table 65. Simple IP Fallback Message Sequence
Step
Description
1
With the IPSec Child SA (Security Association) and TIA already in place, the PDIF sends advertisements to the MS.
2
The MS sends a Registration Request (RRQ) message to the PDIF. The PDIF sends an authentication request to the AAA
server over the RADIUS interface.
3
The AAA server authenticates successfully and sends the IP address of the HA.
4
The PDIF forwards the RRQ message to the HA.
5
The HA denies the request. The PDIF forwards the denial code to the MS.
6
The session setup timer expires and the PDIF goes into fallback mode. The PDIF sends a RADIUS Accounting Start
message.
7
The AAA server sends a RADIUS Accounting Response message.
8
The PDIF updates the HSS with the TIA address of the subscriber.
9
The HSS sends an acknowledgement to the PDIF.