Connect to the remote side using cu
Check that the system is configured for dial-in connections
Examine PPP negotiation in the log file
Link initiation
Negotiate LCP parameters
Perform PAP or CHAP authentication
Negotiate IPCP and other parameters
Link termination
Check that the PPP interface exists
Try to ping the remote side
Check that routing is set up correctly
Interoperating with PPP in Microsoft Windows
Interoperating with 3Com NetBuilder