Take these steps to get debugging logs from pppd and chat:

1. add '-v' to chat's options. (Look in /etc/ppp.)
2. add 'debug' to pppd's options.
3. add '*.debug /tmp/debug' to /etc/syslog.conf
4. touch /tmp/debug
5. kill -HUP `ps auxww | grep syslog | grep -v grep | awk '{print $2}'`
    (restarts syslogd)
6. pppd
7. tail -f /tmp/debug

You'll be able to see how far pppd is getting. When you get pppd working,
undo some of this stuff -- otherwise your PPP account password may be
visible to other users of your system.

jonh@cs.dartmouth.edu

If you have tried starting PPP in the last minute or so,
you can also use a command such as:

    # tail -20 /var/log/messages

to see what's happening.