Packet Data Interworking Function Overview
Cisco ASR 5000 Series Product Overview â–„
Figure 121. Simple IP Fallback Message Sequence
Table 65. Simple IP Fallback Message Sequence
With the IPSec Child SA (Security Association) and TIA already in place, the PDIF sends advertisements to the MS.
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.
The AAA server authenticates successfully and sends the IP address of the HA.
The PDIF forwards the RRQ message to the HA.
The HA denies the request. The PDIF forwards the denial code to the MS.
The session setup timer expires and the PDIF goes into fallback mode. The PDIF sends a RADIUS Accounting Start
message.
The AAA server sends a RADIUS Accounting Response message.
The PDIF updates the HSS with the TIA address of the subscriber.
The HSS sends an acknowledgement to the PDIF.