There are an almost infinite number of ways in which a PPP server can be
set up. In order to connect to your ISP (or corporate PPP server to access
your intranet), you will need to obtain information on how the PPP
server operates.
Because you are using Linux, you may have some difficulty with some ISP
help desks (and work site based PPP intranet servers) which know only
about MS Windows clients.
However, a rapidly growing number of ISPs use Linux to provide their
service - and Linux is also penetrating the corporate environment as
well, so you may be lucky if you do strike problems.
Section Chapter 11 tells you what you need to know about the PPP server
to which you are going to connect - and how to find out the information
you need to know.