Cisco Cisco Packet Data Gateway (PDG)
SaMOG Gateway Overview
▀ Features and Functionality - Base Software
▄ SaMOG Administration Guide, StarOS Release 16
26
This feature enables 4G/3G subscribers to connect to EPC/Internet using the trusted WiFi SSIDs served by EoGRE
enabled Residential Gateways in SaMOG. SaMOG acts as the tunnel endpoint for the EoGRE tunnel initiated from the
Residential Gateway. Using the SSID-based WLAN access, users are authenticated based on the SSID they select to
connect to WLAN. The Residential Gateway/WLC maintains separate SSIDs to provide 3G/4G access, and users can
select the appropriate SSID based on their subscription to obtain 3G or 4G access through the WiFi network.
enabled Residential Gateways in SaMOG. SaMOG acts as the tunnel endpoint for the EoGRE tunnel initiated from the
Residential Gateway. Using the SSID-based WLAN access, users are authenticated based on the SSID they select to
connect to WLAN. The Residential Gateway/WLC maintains separate SSIDs to provide 3G/4G access, and users can
select the appropriate SSID based on their subscription to obtain 3G or 4G access through the WiFi network.
Important:
Currently, EoGRE supports IPv4 addressing only.
With this feature, SaMOG acts as the AAA server and DHCP server to the user equipment (UE) that connects to the
WLAN network. SaMOG processes all the control packets from the UE and maintains the subscriber session to provide
3G/4G access. Acting as the DHCP-server, SaMOG creates the PDP context with GGSN/PGW and obtains the IP
address to allocate to the UE through DHCP-Response in the access-side. The interface with GGSN is similar to the
TTG's Gn' interface with GGSN for 3G, and the existing SaMOG's S2a interface with PGW for 4G. The DHCP and data
packets originating from the UE are forwarded by the Residential Gateway/WLC node through the EoGRE tunnel to
SaMOG.
WLAN network. SaMOG processes all the control packets from the UE and maintains the subscriber session to provide
3G/4G access. Acting as the DHCP-server, SaMOG creates the PDP context with GGSN/PGW and obtains the IP
address to allocate to the UE through DHCP-Response in the access-side. The interface with GGSN is similar to the
TTG's Gn' interface with GGSN for 3G, and the existing SaMOG's S2a interface with PGW for 4G. The DHCP and data
packets originating from the UE are forwarded by the Residential Gateway/WLC node through the EoGRE tunnel to
SaMOG.
The MRME service maintains all the access network parameters (Radius client and access client details) locally. The
MRME service determines the session’s access-type and if a request should be accepted or rejected, based on the NAS
IP (AVP in the Access-Request/ Accounting-Request) or Source IP of the request (if NAS IP AVP is not available), by
looking up the local configuration and conveys the same to CGW for session setup.
MRME service determines the session’s access-type and if a request should be accepted or rejected, based on the NAS
IP (AVP in the Access-Request/ Accounting-Request) or Source IP of the request (if NAS IP AVP is not available), by
looking up the local configuration and conveys the same to CGW for session setup.
SaMOG as a Default Gateway
The SaMOG Gateway can act as the first-hop L3 router (default gateway) for the UE, and the UEs can forward data
traffic directly to SaMOG using the EoGRE tunnel from the Residential Gateway/WLC. For 3G access, the default
gateway IP address is obtained from the local configuration and supplied by P-GW for 4G access over the S2a interface.
traffic directly to SaMOG using the EoGRE tunnel from the Residential Gateway/WLC. For 3G access, the default
gateway IP address is obtained from the local configuration and supplied by P-GW for 4G access over the S2a interface.
UEs wanting to send data traffic will resolved the MAC address of the default gateway using an ARP request which is
forwarded by the residential gateway/WLC over EoGRE using the mapped VLAN. The SaMOG Gateway responds
with the virtual MAC address in the ARP response to enable data packets to reach SaMOG from the UE.
forwarded by the residential gateway/WLC over EoGRE using the mapped VLAN. The SaMOG Gateway responds
with the virtual MAC address in the ARP response to enable data packets to reach SaMOG from the UE.
With this release, SaMOG default gateway does not handle ICMP packets. The ICMP packets are considered as data
and forwarded to GGSN/P-GW.
and forwarded to GGSN/P-GW.
Offline Charging Support
The SaMOG Gateway supports generation of CDR files for offline charging. Offline charging works by collecting
charging information concurrently with resource usage and passes the information through a chain of logical charging
functions. At the end of the process, CDR files are generated by the network and transferred to the network operator's
Billing Domain.
charging information concurrently with resource usage and passes the information through a chain of logical charging
functions. At the end of the process, CDR files are generated by the network and transferred to the network operator's
Billing Domain.
For more information on offline charging for the SaMOG Gateway, refer to the SaMOG Gateway Offline Charging
chapter of this guide.
chapter of this guide.
SNMP Traps
The SaMOG Gateway generates SNMP traps for the SaMOG service startup and shutdown events. For detailed
descriptions of the traps, refer to the SNMP MIB Reference guide.
descriptions of the traps, refer to the SNMP MIB Reference guide.