ZyXEL Communications Vantage Service Gateway VSG-1200 V2 User Manual

Page of 282
VSG-1200 V2 User’s Guide
81
Chapter 9 Authentication
The VSG redirects the guest’s web browser to a login screen at CAS. 
The guest enters the provided access information. 
Once authentication is successful, CAS informs VSG to allow Internet access to the 
guest. 
9.1.3  Built-in Authentication
The built-in authentication method is useful if you do not have a RADIUS server. You can use 
the built-in subscriber database to manage the subscribers. With the built-in authentication, the 
VSG provides three sets of preconfigured scenarios that you can choose for easy and simple 
setup. For billing, use either a PMS or the built-in billing mechanism to set up accounting 
information.
9.1.4  RADIUS
The VSG supports Remote Authentication Dial-In user Service (RADIUS). By integrating 
RADIUS with the VSG, you can set up the subscriber database on the RADIUS server. In 
addition to subscriber information, the subscriber database may hold the Internet usage time 
period each subscriber is allocated. For example, when a subscriber logs in, the RADIUS 
server will send the time allocation information (such as session time-out) to the VSG, which 
uses this information to control the subscriber’s connection.
9.1.4.1  RADIUS Accounting
The VSG sends “accounting start” and “accounting stop” messages to the RADIUS server, 
which uses these messages to accurately track subscriber Internet usage.
The VSG provides two accounting methods: Accumulation and Time to Finish.
• The Accumulation accounting method allows multiple re-logins until the allocated time 
period or until the subscriber account is expired. The VSG accounts for the time the 
subscriber logs in for Internet access.
• The Time to Finish accounting method is good for one-time logins. Once a subscriber 
logs in, the VSG stores the MAC address of the subscriber’s computer for the duration of 
the time allocated. Thus the subscriber does not have to enter the user name and password 
again for re-login within the allocated time. Once activated, the subscriber account is 
valid until the allocated time is reached even if the subscriber disconnects Internet access 
for a certain period within the allocated time. For example, if Joe purchases a one-hour 
time-to-finish account. He starts using the Internet for the first 20 minutes and then 
disconnects Internet access to go to a 15-minute meeting. Then he only has 25 minutes 
left on his account.