A General Packet Radio System (GPRS)-based communications network that
includes a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support
Node (GGSN) assigns an IPv4 address to a mobile station in a GPRS-based
network that conserves IPv4 addresses and simultaneously maintains
end-to-end security and application friendliness. The SGSN receives from
a mobile station an Activate PDP Context Request message having an APN
field that requests a private or a public network address. The SGSN then
sends a Create PDP Context Request message to the GGSN. The GGSN assigns
a private or a public network address to the mobile station, and sends a
Create PDP Context Response message to the SGSN. In turn, the SGSN sends
an Activate PDP Context Accept message to the mobile station assigning a
private or a public network address to the mobile station.