BG:

The Border Gateway or BG is a network element within the GPRS core network. As the figure below shows, the BG provides for Inter-PLMN transactions, that is, when subscribers are roaming outside their Home-PLMN.
Major functions of the BG evolve around security and message screening (firewall functionality). As such, two issues need to be considered:
  • Packet data with unappropriate or even hazardous formating need to be prevented from entering a PLMN.
  • Packet data with criminal intention to overload or crash a PLMN need to be refused.

The BG doesn't need to be a separate network element but can be integrated within one SGSN or one GGSN.

The Border Gateway as part of the GPRS Core Network

[2GTS 03.60 / 3GTS 23.060]