I am using DLINK GLB 802 C.

The router is connected via the splitter supplied with it. The connection to the phone is connected to a phone on the next room. My dad often keeps the phone disconnected coz he doesnt want to be disturbed.

Problem is when that phone is unplugged the ADSL link led of the router becomes unstable. It blinks for a while & then goes dark. This cycle happens forever.

I dont understand why the disconnection of the phone is affecting the adsl link.