I have CenturyLink... And a Actiontec C1000a VDSL modem.

Actiontec  SUCKS.   I HAD to put it into bridge mode to get it to NOT hang as you described.  It would simply go mind-dead, but NOT completely.

Not only that, it would throw an error when accessing the built-in webpage.  Would randomly decide NOT to save settings you gave it.  JUST F'ing TRASH! Tried THREE different BRAND-NEW modems and they ALL did / do it.

Worst piece of garbage I've ever had the displeasure of owning.

Wayne