For subscriber sessions using Proxy Mobile IP, R-P and PPP sessions get established between the MN and the PDSN as
they would for a Simple IP session. However, the PDSN/FA performs Mobile IP operations with an HA (identified by
information stored in the subscriber‘s profile) on behalf of the MN (i.e. the MN is only responsible for maintaining the
Simple IP PPP session with PDSN).

The MN is assigned an IP address by either the PDSN/FA or the HA. Regardless of its source, the address is stored in a
mobile binding record (MBR) stored on the HA. Therefore, as the MN roams through the service provider‘s network,
each time a hand-off occurs, the MN will continue to use the same IP address stored in the MBR on the HA.

Note that unlike Mobile IP-capable MNs that can perform multiple sessions over a single PPP link, Proxy Mobile IP
allows only a single session over the PPP link. In addition, simultaneous Mobile and Simple IP sessions will not be
supported for an MN by the FA that is currently facilitating a Proxy Mobile IP session for the MN.

The MN is assigned an IP address by either the HA, a AAA server, or on a static-basis. The address is stored in a mobile
binding record (MBR) stored on the HA. Therefore, as the MN roams through the service provider‘s network, each time
a hand-off occurs, the MN will continue to use the same IP address stored in the MBR on the HA.