When supporting Mobile
IP, the system can be configured to perform the role of a FA, an
HA, or both. This section describes the engineering rules for the
Pi interface when using the system as a FA.
The following engineering
rules apply to the Pi interface between the FA and HA:
-
A Pi
interface is created once the IP address of a logical interface
is bound to an FA service.
-
The
logical interface(s) that will be used to facilitate the Pi interface(s)
must be configured within the egress context.
-
FA services
must be configured within the egress context.
-
If the
system is configured as a FA is communicating with a system configured
as an HA, then it is recommended that the name of the context in
which the FA service is configured is identical to the name of the
context that the HA service is configured in on the other system.
-
Each
FA service may be configured with the Security Parameter Index (SPI)
of the HA that it will be communicating with over the Pi interface.
-
Multiple
SPIs can be configured within the FA service to allow communications
with multiple HAs over the Pi interface. It is best to define SPIs
using a netmask to specify a range of addresses rather than entering
separate SPIs. This assumes that the network is physically designed to
allow this communication.
-
Depending
on the services offered to the subscriber, the number of sessions
facilitated by the Pi interface can be limited.