To provide the roaming MS with Simple IPv41 based access across cdma2000®2 packet data
systems which are managed by different administrative domains, an inter-working scheme is
required. The inter-working scheme allows the home domain to control the delivery of services to
the roaming MS. A home domain control model for Simple IP based access enables the roaming
MS with home domain access, with minimum requirements in the foreign domain to which the
roaming MS is connected. This specification describes an inter-working scheme based on the
tunneling of the Simple IP packet data traffic of the roaming MS, between a foreign domain and a
home domain.