Serving Gateway (S-Gw); Pdn Gateway (P-Gw) - Cisco ASR 5000 Series Administration Manual

HRPD Serving Gateway Overview
Authentication
Bearer management functions including dedicated bearer establishment
HRPD access node (terminating S101 reference point) selection for handovers to HRPD
Transparent transfer of HRPD signalling messages and transfer of status information between E-UTRAN and
HRPD access, as specified in the pre-registration and handover flows

Serving Gateway (S-GW)

For each UE associated with the EPS, there is a single S-GW at any given time providing the following basic functions:
Terminates the interface towards E-UTRAN (S1-U)
Functions (for both the GTP-based and the PMIP-based S5/S8) include:
Handling of Router Solicitation and Router Advertisement messages if PMIP based S5 and S8 are used
MAG for PMIP based S5 and S8

PDN Gateway (P-GW)

For each UE associated with the EPS, there is at least one P-GW providing access to the requested PDN. If a UE is
accessing multiple PDNs, there may be more than one P-GW for that UE. The P-GW provides the following basic
functions:
Terminates the interface towards the PDN (SGi)
PGW functions (for both the GTP-based and the PMIP-based S5/S8) include:
OL-22984-01
local mobility anchor point for inter-eNodeB handover
mobility anchoring for inter-3GPP mobility (terminating S4 and relaying the traffic between 2G/3G
system and P-GW)
ECM-IDLE mode downlink packet buffering and initiation of network triggered service request
procedure
lawful intercept
packet routing and forwarding
transport level packet marking in the uplink and the downlink (e.g. setting the DiffServ Code Point)
Accounting
per-user packet filtering (e.g. deep packet inspection)
lawful intercept
UE IP address allocation
UL and DL service level charging, gating control, and service level rate enforcement
DL rate enforcement based on AMBR (Aggregate Max Bit Rate) and based on the accumulated MBRs
of the aggregate of SDFs with the same GBR QCI
Cisco ASR 5000 Series HRPD Serving Gateway Administration Guide ▄
eHRPD Network Summary ▀