Why does my family’s wide band always fall the line? Strives for the router establishment!

My family altogether has two computers, with the Mercury MW54R router, fell the line frequently recently.
When surfer, formerly displayed normally, after having used some time, only then presents the line.Cat’s ADSL lamp has glittered, is unable to connect automatically quite a while.
Only then discovered until today, after falling the line, may change to a computer by the cat direct selection surfer.
Then meets again the information the router, may also use some time normally.So relapse..
Removed the telecommunication wide band the question, between the connection router and cat’s network line is trades newly.
Wants to consult, is between the router and cat’s establishment question?
The cat is TP-LINK TD-8620
After router formatting, reset.Right, you trade newly