SGSN	GGSN	Border   Gateway
DNS	NMS	Charging   Gateway

Private IP
network which is isolated and invisible to external networks or GPRSsubscribers

Carries
subscriber IPtraffic in GPRSspecific tunnels (GTP)

Carries GPRS
specific signaling between GSNs

Carries
charging data from GSNs to Charging Gateway

Carries GPRS
core management information (SNMP, Web)

Interconnectd
GPRS Core network comprise a large private network