The ISG 2000 is a fully integrated FW/VPN/IDP system with multi-gigabit performance, a modular architecture and rich virtualization capabilities. The base FW/VPN system allows for up to four I/O modules and three security modules for IDP integration. The ISG 2000 can be upgraded to support GPRS (General Packet Radio Service) to provide stateful firewalling and filtering capabilities and to protect key nodes like the SGSN and the GGSN in the mobile operators' network.