Cisco Cisco Packet Data Gateway (PDG)

 

▄  SaMOG Administration Guide, StarOS Release 16  

The Packet Data Network Gateway (P-GW) is the network node that terminates the SGi interface towards the PDN. The 
P-GW provides connectivity to external PDNs for the subscriber UEs by being the point of entry and exit for all 
subscriber UE traffic. A subscriber UE may have simultaneous connectivity with more than one P-GW for accessing 
multiple PDNs. The P-GW performs policy enforcement, packet filtering, charging support, lawful interception, and 
packet screening. The P-GW is the mobility anchor for both trusted and untrusted non-3GPP IP access networks. For 
trusted non-3GPP IP access networks, the P-GW hosts the LMA (Local Mobility Anchor) function for the PMIP-based 
S2b interface, and the SaMOG Gateway’s CGW service hosts the LMA function for the PMIP/EoGRE-based S2a 
interface. 

The GGSN works in conjunction with Serving GPRS Support Nodes (SGSNs) within the network and routes data traffic 
between the subscriber’s Mobile Station (MS) and a Packet Data Networks (PDNs) such as the Internet or an intranet. 
GGSN can be configured to support Mobile IP and/or Proxy Mobile IP data applications to provide mobility for 
subscriber IP PDP contexts. When supporting these services, the system can be configured to either function as a GGSN 
and Foreign Agent (FA), a standalone Home Agent (HA), or a GGSN, FA, and HA simultaneously within the carrier's 
network. 

The 3GPP Authentication, Authorization, and Accounting (AAA) server provides UE authentication via the Extensible 
Authentication Protocol - Authentication and Key Agreement (EAP-AKA) authentication method. 

The Home Subscriber Server (HSS), is the master user database that supports the IP Multimedia Subsystem (IMS) 
network entities. It contains subscriber profiles, performs subscriber authentication and authorization, and provides 
information about the subscriber's location and IP information. 

The PCRF (Policy and Charging Rules Function) determines policy rules in the IMS network. The PCRF operates in the 
network core, accesses subscriber databases and charging systems, and makes intelligent policy decisions for 
subscribers. 

The trusted non-3GPP IP access contains one or more WLAN access points. An access point terminates the UE's 
WLAN IEEE 802.11 link defined in IEEE standard 802.11-2007. 

The following table provides descriptions of the logical network interfaces supported by the SaMOG Gateway in the 
EPC network.