The IP Services
Gateway (IPSG) is a stand-alone device capable of providing managed services to
IP flows. The IPSG is situated on the network side of legacy, non-service
capable GGSNs, PDSNs, HAs, and other subscriber management devices. The IPSG
can provide per-subscriber services such as Enhanced Charging Service,
Application Detection and Control, and others.
The IPSG allows the
carrier to roll out advanced services without requiring a replacement of the
HA, PDSN, GGSN, or other access gateways and eliminates the need to add
multiple servers to support additional services.
IPSG only requires a
RADIUS request (access and accounting messages) with all the required mandatory
attributes to create a session. Currently, IPSG supports GGSN (2G, 3G), PDSN,
HA, Broadband Remote Access Server (B-RAS). IPSG does not support the radio access types
(RAT) of 4G (EUTRAN) and Wi-Fi and hence cannot be deployed with P-GW (with 4G,
Wi-Fi access, 2G/3G SGSN based RATs). For the list of AAA attributes supported
by IPSG, refer to the
Gateway AAA AVP Support appendix.