Quick repetitive disconnects

Question

I've my router setup properly, but I encounter quick repetitiv e disconnects from time to time.Usually at disconnect, the power indicator(lamp) of the router turns off for ashort time.I tried to resolve that, I had 2 phone sets, one is connected directly to the source phone line through afilter and the router is connected directly to this phone line also.I removed this phone set, the disconnecting is less intense now, but it's still occuring.The other phone set is connected through a splitter.