If you can't get your PPP link to work, go back through this document and check everything - in conjunction with the output created by "chat-v..." and "pppd -d" in you system log.
Also consult the PPP documentation and FAQ plus the other documents mention herein!
If you are still stuck, try the comp.os.linux.misc and comp.os.linux.networking newsgroups are reasonably regularly scanned by people that can help you with PPP as is comp.protocols.ppp
You can try sending me personal email, but I do have a day job (and a life) and I do not guarantee to respond quickly (if at all) as this depends on my current work load and the state of my private life!
In particular - DO NOT POST REAMS OF DEBUGGING OUTPUT TO THE NEWS GROUPS NOR SEND IT TO ME BY EMAIL - the former wastes huge amounts of network bandwidth and the latter will be consigned to /dev/null (unless I have specifically requested it).