GPRS infrastructure
Three major types of IP addressable GPRS Network Elements for roaming in each operators network
- Serving GPRS Support Node (SGSN) -> radio
- Gate GPRS Support Node (GGSN) -> land IP network
- Domain Name Server (DNS) - for name resolution
In roaming, SGSN in one network connects to GGSN in another
Networks operators linked by inter-PLMN backbone
Common IP addressing scheme required for use across the GPRS inter-PLMN backbone and inside the operators’ networks (SGSN, GGSN etc)