Cisco Cisco IOS Software Release 12.2(16)B

SSG accounting must be enabled in order for the SSG Prepaid enhancements features to be used. 
SSG accounting is enabled by default. If it has been disabled, enable it by using the ssg accounting 
command in global configuration mode.

The SSG Prepaid enhancements features require the authentication, authorization, and accounting 
(AAA) server to have prepaid billing support.

The volume quota is for combined upstream and downstream traffic.

Before you use the SSG Prepaid Enhancements feature, you should understand the following concepts:

The SSG is a switching solution for service providers that offer intranet, extranet, and Internet 
connections to subscribers that use broadband access technology such as digital subscriber lines, cable 
modems, or wireless networks to allow simultaneous access to network services.

SSG works in conjunction with the Cisco Service Selection Dashboard (SSD) or its successor product, 
the Cisco Subscriber Edge Services Manager (SESM). Together with the SESM or SSD, SSG provides 
subscriber authentication, service selection, and service connection capabilities to subscribers of 
Internet services. Subscribers interact with an SESM or SSD web application using a standard Internet 
browser.