Not solved till now. I've observed that my SNR margin keeps on decreasing constantly with time! It drops from 24 to 13-14. I think this is the main reason for disconnection. So I've found using PPPoE mode as a simple solution to the problem. I'm not liking it much, with all the port forwarding hassles to take care of, but I don't have any choice. I don't like the telnet reboot method either. Anyways, I can't do anything about it. A question - Does PPPoE mode revive automatically if it freezes at some point in the night?