[pptp-server] Can't get PoPToP to work when tunnel is via ISP and modem link

[John Matthews]

All,
  I've got PoPToP working when the tunnel is across a LAN but I can't seem
to get it working when the tunnel goes via my ISP and a modem link. Has
anyone got PoPToP working like this ? Otherwise do I take it from the
following entry in the TODO list that I'm going to have to wait for a future
version.
"990802  -  We don't actually implement any kind of window protocol,
congestion control, etc, etc. Very simple algorithm which works well on LANs
and good performance links but could be improved for slow distant
dialups/bad routing and links."

John Matthews