Cisco Cisco ASR 5000
MME
The Cisco MME (Mobility Management Entity) is the key control node for the LTE access network. It works
in conjunction with the eNodeB and the Cisco S-GW to control bearer activation and deactivation. The MME
is typically responsible for selecting the Cisco P-GW for the UEs to access the PDN, but for secure access
from untrusted non-3GPP IP access networks, the ePDG is responsible for selecting the P-GW.
in conjunction with the eNodeB and the Cisco S-GW to control bearer activation and deactivation. The MME
is typically responsible for selecting the Cisco P-GW for the UEs to access the PDN, but for secure access
from untrusted non-3GPP IP access networks, the ePDG is responsible for selecting the P-GW.
S-GW
The Cisco S-GW (Serving Gateway) routes and forwards data packets from the 3GPP UEs and acts as the
mobility anchor during inter-eNodeB handovers. The S-GW receives signals from the MME that control the
data traffic. Every 3GPP UE accessing the EPC is associated with a single S-GW.
mobility anchor during inter-eNodeB handovers. The S-GW receives signals from the MME that control the
data traffic. Every 3GPP UE accessing the EPC is associated with a single S-GW.
P-GW
The Cisco P-GW (Packet Data Network Gateway) 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 PMIP-based S2a and S2b interfaces, the P-GW
hosts the LMA (Local Mobility Anchor) function.
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 PMIP-based S2a and S2b interfaces, the P-GW
hosts the LMA (Local Mobility Anchor) function.
3GPP AAA Server
The 3GPP AAA (Authentication, Authorization, and Accounting) server provides UE authentication via the
EAP-AKA (Extensible Authentication Protocol - Authentication and Key Agreement) authentication method.
EAP-AKA (Extensible Authentication Protocol - Authentication and Key Agreement) authentication method.
HSS
The HSS (Home Subscriber Server), is the master user database that supports the IMS (IP Multimedia
Subsystem) network entities. It contains subscriber profiles, performs subscriber authentication and
authorization, and provides information about the subscriber's location and IP information.
Subsystem) network entities. It contains subscriber profiles, performs subscriber authentication and
authorization, and provides information about the subscriber's location and IP information.
PCRF
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.
operates in the network core, accesses subscriber databases and charging systems, and makes intelligent policy
decisions for subscribers.
ePDG Administration Guide, StarOS Release 19
4
Evolved Packet Data Gateway Overview
Network Elements