pppsetup is a utility that helps you connect to an Internet Service
Provider's ppp services. It walks you through the configuration process
and then writes a custom connect script. Running the program should be
sufficiently informative.

pppsetup writes a modem dialing script in chat, which is a simple
scripting language that can talk and listen to a modem. I recommend that
you use pppsetup to get configured, and then write a dcon script to
replace the chat script.