Cisco Cisco Packet Data Gateway (PDG)

 

processing any control or data packets. After the packets are encapsulated or decapsulated, the session is handled in the 
same way as that of L3IP or IP@W deployment models. The IPoGRE functionality is achieved using the StarOS GRE 
tunnel feature, and one-to-one mapping between the GRE tunnel interfaces (or same TWAN profile multiple GRE 
tunnel interfaces) and VRFs. 

  The IP over GRE model requires a GRE Interface Tunneling license to create GRE tunnels. For more 

information on licenses, contact your Cisco account representative. 

 

The SaMOG Gateway supports VLAN encapsulation on the L3IP access-type to ensure a scalable deployment model. 
The SaMOG Gateway adds an extra VLAN header next to the Ethernet header and the session is handled in the same 
way as that of the L3IP or IP@W deployment models. The IPoVLAN functionality is achieved using the StarOS VLAN 
feature, and one-to-one mapping between the VLANs (or same TWAN profiles) and VRFs. 

SaMOG supports proxy-based authentication, and session creation based on the MAC address received in the Access-
Request messages. SaMOG acts as both authentication and accounting proxy. In accordance to 3GPP 23.402 standards, 
a PDN connection establishment is completed before the Radius Access-Accept is sent to the WLC. 

The SaMOG Gateway functions in a server mode acting as a AAA accounting server in the uplink direction to receive 
the accounting requests. The accounting start message is used between the WLC and the SaMOG Gateway to 
communicate the IP@WLAN assigned by the WLC to the SaMOG Gateway. The server mode for the SaMOG Gateway 
is enabled when there is no accounting server configuration present in the Operator Policy Configuration Mode. 

The SaMOG Gateway provides support for different models for the UE Home Address (UE-HA) and UE Network 
Address (UE-NA) as follows: 



 

The WLAN assigns an address directly to the UE and communicates it to the SaMOG Gateway through an 

accounting start-request message with the Framed-IP-address set to IP@W. 

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The WLC relays the DHCP requests to the SaMOG Gateway, and the SaMOG Gateway provides the address it 

receives from the P-GW. 



 

The WLC relays DHCP requests to the SaMOG Gateway, and the SaMOG Gateway assigns the address from its 

local pool and shares the same to the UE (For Local Breakout (Basic)). 



 

The SaMOG Gateway assigns the address from the P-GW to the UE. 

The SaMOG gateaway can perform static NAT when the UE-HA and the UE-Na are not the same. Static NAT is 
achieved through the Enhanced Charging Service's (ECSv2) Firewall and NAT functionality. 

SaMOG supports DHCP server at system level for L3IP models where the UE session is identified by parsing the DHCP 
options inside the DHCP packets (using DeMUX). SaMOG supports DHCP packets in-band where the VLAN or GRE 
tunnel from which the DHCP packets are received is considered to be the same tunnel to receive the data path traffic.