> ok now all it does is this:
 ...
> May 18 18:58:44  pppoe[1369]: PPP session is 636

That's great, you have a PPPoE session established. Now a "normal" PPP
negotiation starts.

> May 18 18:58:45  pppd[1367]: LCP terminated by peer

and, unfortunately, failed. You probably have your name/password wrong,
please double-check. I think there are directions in the networking FAQ
how to enable debug output in pppd to track this further. (I have no
clue about this, it's been years since I last had to do it, sorry).

> May 18 18:58:45  pppoe[1369]: Session terminated -- received PADT from
> access concentrator

And then the remote side disconnects the session again. That's ok, after
LCP failed.

Martin