Ive been using my Nayatel broadband connection for 2 years now and for the past 4 months I have been getting some disconnection problems. At first the disconnection were quite rare and happened only once in a while, but now the disconnection problem is quite frequent.
Have you checked your cables that they are all connected properly? It may sound stupid but sometimes little things can make a difference. If the problem still persists then I would suggest you call Nayatel customer care, and ask one of their guys to come and have a look at the connection.