A Packet Data Serving Node (PDSN) provides access to the Internet, intranets and applications servers for mobile stations utilizing a cdma2000 Radio Access Network (RAN). Acting as an access gateway, PDSN provides simple IP and mobile IP access, foreign agent support, and packet transport for virtual private networking. It acts as a client for Authentication, Authorization, and Accounting (AAA) servers and provides mobile stations with a gateway to the IP network. Mobility differentiates Cisco’s PDSN from the traditional routed network. With PDSN, the host can move and, therefore, there must be a way to forward packets to it. Cisco's PDSN solution offers a secure way to provide packet data services to mobile stations.