Basic Access types

? Transparent access to the Internet

GGSN has no
active role in user authentication

Subscriber IP
address static or allocated by GGSN from operators address space

Operator acting
as ISP providing Internet access and possibly own Value Added Services (email,
web etc)

? Non-Transparent access to Intranets, ISPs

GGSN provides
user authentication towards RADIUS server

Subscriber IP
address allocated from intranet address space

This is a
typical intranet access case

? The same GGSN can provide both Transparent and
Non-Transparent Access Points