Serial Laplink

I am a Linux newbie and I have just connected my old lap (linux) with my Win
XP desktop, following the instructions in the HOWTO Serial Laplink
(nullmodem cable).

Problems found:

Linux was the server and WinXP the client. I have found a veeeeeery slooooow
connection (even if I have set 115200). After connected the 2 PCs, I have
run Explorer with an ftp session in order to get or download files to the
lap, but it was incredibly slow. On the lap I am running kernel 2.0.30 and
ppp 2.3.5.

Suggestions?