Business internet down intemittently

I have been having intermittent internet access problems for weeks now.  It can last for hurs with access being slow sometimes and unavailable at other times, then fine for a while. It does not appear the gateway is losing connection so much as no response from its uplink side. 

I hoped it would quit, but we seem to have it every day or so.  It is noticed usually in the mornings, but this afternoon as well.

Thanks,

David