A method for assigning unique identifiers for allowing communication
between a GPRS (General Packet Radio Service) system and a RADIUS (Remote
Authentication Dial In User Service) server. The method includes
connecting one or more external networks to the GPRS system and
identifying the or each network with an APN (Access Point Name), and
assigning to an or each APN external network a gateway address. An
APN-external network authentication request is passed from a GGSN
(Gateway GPRS Support Node) to the RADIUS server. The RADIUS server
provides to the GGSN upon such request a subscriber IP (Internet
Protocol) address to be stored in the GGSN (Gateway GPRS Support Node).
The subscriber IP address is unique for the respective APN external
network defined in the GGSN. The GGSN combines the APN gateway address
and the subscriber IP address to form a unique subscriber identifier; and
sends that identifier to the RADIUS server for accounting, e.g., in the
form of an ASCII string.