[pptp-server] Question: Is it possible to use NAT at each end of the connection..?

[Mark Pearson]

I have poptop working very nicely between a dialup client and a natted
server.

What i need to know is, can I use a client connection with say a netgear
rh348 isdn router to connect into my current server (gnatbox)?  Is it just a
case of the netgear router allowing GRE through?

Any advice/help would be much appreciated :-)