hi gang ,
am gonna build a software to facilitate file transfer across dial up wan connections.
assume i have no dialup connection in access!

i know that winsock ease the case by letting me write my program using socket as if both my server and client are loacated in a lan , so with just using some socket programming i can build up the system.
first if i am wrong correct me !
then am faced with security freaks which i guess i might use pptp
in middle.
so what are challenges in this case .

plus if anyone has captured ppp packets before NCP comes up ,please give me clue in this case .
ppp establishment in order :
1- LCP (framing around layer3 datagram)
2- authentication (...)
3- NCP (negociating layer3 parameters between server and client).

before step 3 no one can capture using winpcap enabled application ...
so please anyone gimmi e clue..
tanxc in advance