Cisco Cisco IOS Software Release 12.4(15)T

Before implementing SSG Mobile Wireless enhancements, SSG must be enabled by using the ssg 
enable command.

This enhancement supports General Packet Radio Service/Extensible Authentication Protocol 
(GPRS/EAP) for the SSG. You should understand the following technologies:

The Serving GPRS Support Node (SGSN) connects the radio access network (RAN) to the 
GPRS and the 3G Universal Mobile Telecommunication System (UMTS) core and tunnels user 
sessions to the GGSN. For more information, see

.

The SSG EAP Transparency feature enables the Cisco Service Selection Gateway (SSG) on a 
Cisco router to act as a RADIUS proxy during EAP authentication and to create the host. For 
more information, see the 

SSG EAP Transparency 

feature module. 

The Access Zone Router (AZR) provides connectivity, client address management, security 
services, and routing across a WAN from each access point to an operator’s point of presence 
(POP) or data center. For more information, see the 

document. 

SSG does not process multicast packets.

To implement SSG Mobile Wireless enhancements, you should understand the following concepts:

While the Service Selection Gateway (SSG) is acting as a RADIUS proxy for the Gateway GPRS 
Support Node (GGSN), it also receives all accounting packets: accounting-on-off packets as well as 
accounting-start-stop packets. By default, only accounting-on-off packets are forwarded to the real 
authentication, authorization, and accounting (AAA) server.

The forward accounting-on-off command allows you to override this default behavior and to suppress 
transparent proxying of accounting packets.