Chapter 1 What’s New for FortiOS 5.0 : New features in FortiOS 5.0 Patch 4 : RADIUS Accounting
  
RADIUS Accounting
Accounting servers can now be configured in a RADIUS setting. For each RADIUS server, four more accounting servers can be created.
The following example adds an accounting server to a RADIUS server:
config user radius
edit rad159
set server 172.16.62.159
set secret asdfasdf
config accounting-server
edit 1
set status enable
set server 175.18.5.36
set secret asdfasdf
end
end