Sam, I've got the same company; 10Mbps download and about .75 Mbps upload.  CenturyLink is generally pretty good, but occasionally . . . . Tuesday morning I was on the Internet early, but then about 9 a.m., I noticed the "Internet" light was out on the modem.  So I did a little checking to see if it would reset; finally decided to call CenturyLink.  No wonder I had no Internet service; the phone was dead.  So I called on my cell phone and talked to a lady who wasn't too bright for 13 minutes.  She suggested I unplug everything from all the phone jacks, then plug in a corded phone to each jack, etc., etc.  I told her we were just wasting time and I just wanted it fixed.  So she said she'd send a repairman out, but it might be 24 hours before he got here.  About an hour and a quarter later, I noticed the light was back on the modem, Internet worked, but not the phones, so I unplugged all the phones again and plugged them back in and they worked.  I expected to hear from CenturyLink, but no one every called and no one ever showed up.  But anyway, it's worked ever since.