how to change PPP timeout value

Hi,
I am using Windows XP to intiate a PPP call to connect to remote linux
system (configured as host). The network delay I am seeing is more than
500msec. Because this, everytime I initiate a call from XP pc, it doesnt get
the reply within default timeout and call doesnt get established.

Can anybody tell me how I can change (increase) the PPP timeout value so
that the call gets established.

Thanks.