Actually, I think the big reason might be the "/" that needs to go into
your user name.  Try quoting it:  ELN\/xxxxx

Also, if you haven't done so already, put a -v in the chat command line,
and add an entry to your /etc/syslogd.conf to enable local2:

    local2.*	 /dev/console

Then watch the console output to see why you're failing to log in to your
ppp server.