Common Packet Core (2G/3G/4G) Network Interfaces:
- Gn Interface: Connects the SGSN to GGSNs and other SGSN in the same PLMN allowing exchange of signaling and payload.
- Gom Interface: Connects the SGSN to operation and maintenance (O&M) equipment in the O&M network allowing an operator to communicate with the SGSNs/GGSNs.
- Gp Interface: Connects the SGSN to GGSNs located in other PLMNs.
- Gb Interface: Connects the SGSN to Base Station Controller (BSCs) in the GSM for payload transporting and signaling.
- Gf Interface: Connects the SGSN to Equipment Identity Register (EIR)
- Gr Interface: Connects the SGSN to Home Location Register (HLR)
- IuU Interface: Designates the Iu User plane, connects the SGSN to Radio Network Controllers (RNCs) in WCDMA RAN for payload transport.
- IuC Interface: Designates the Iu Control plane, connects the SGSN to RNCs in the WCDMA RAN for signaling
- Gy interface: connects the GGSN and PGW to an Online Charging System (OCS), allowing credit control for user traffic.
- Gx interface: connects the GGSN and PGW to the Policy and Charging Rules Function (PCRF), allowing the GGSN and PGW to receive authorization and policy control information for SACC traffic.
- Gi interface: connects the GGSN to a PDN, allowing exchange of signaling and payload. The PDN can be an ISP network or a corporate network. If RADIUS is used, the Gi interface connects the GGSN to the RADIUS server.
