Packet Data Interworking Function Overview
â–„ Cisco ASR 5000 Series Product Overview
Simple IP Fallback Minimum Requirements
There are certain minimum requirements for simple IP fallback, as follows:
There must be a context defined in the CLI configuration.
The default subscriber must be defined in the CLI configuration.
Mobile IP Simple IP Fallback must be defined in the CLI configuration. For example:
The MS has to request MIP by sending an RRQ message to the PDIF/FA. If the MS indicated an intent to use
mobile IP (or was configured with the MIP_Required parameter) but failed to send an RRQ message, the IPSec
session would be disconnected rather than completing a simple IP fallback call.
On supported networks, the PDIF/FA only assumes simple IP fallback mode if mobile IP is attempted but fails
when the MS tries to use mobile IP as the first choice but encounters a problem such as the HA not responding.