Cisco ASR 5000 Series Administration Manual page 157

GGSN and Mobile IP Service in a Single System Configuration Example
Figure 32. Call Processing When Using the System as a GGSN, FA, and HA
BSS/UTRAN
Context (Ctx.)
Interface
Service or
Configuration (Cfg.)
1. A Create PDP Context Request message for a subscriber session is sent from the SGSN to the GGSN service
over the Gn interface. The message contains information such as the PDP Type, APN, and charging
characteristics.
2. The GGSN determines whether or not it is configured with an APN identical to the one specified in the message.
If so, it determines how to process the session based on the configuration of the APN. In this case, it is
determined that Mobile IP must be used. From the APM configuration, the system also determines the context
in which the FA service is configured.
3. If subscriber authentication is required, the GGSN authenticates the subscriber by communicating with a
RADIUS server over the AAA interface.
4. The GGSN returns an affirmative Create PDP Context Response to the SGSN over the Gn interface. The home
address assigned to the mobile as part of the response is 0.0.0.0 indicating that it will be reset with a Home
address after the PDP context activation procedure.
OL-22944-02
CGF
11
6
1
4 5 9
SGSN
GGSN/FA/HA
Source
Ctx.
GTPP
Ga
Cfg.
Net. Req.
PDP Ctx.
Cfg.
G
GGSN-
n
Service
Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide ▄
Using the System as Both a GGSN/FA and an HA ▀
AAA Server
3
10
Dest. Ctx.
Auth.
AAA
Cfg.
DHCP
2
DHCP
Cfg.
APN
Gi
Cfg.
IP Address
Pool Cfg.
MIP Dest. Ctx.
7
FA-Srvc.
ICC
8
Gi
HA-Srvc.
Packet Data Network