Sucking Eggs, Zombie Users or PC's (Take Your Choice).
For all those niggling loss of connectivity issues my users used to experience across North America, I used to remote in, turn off the NIC power management in device manager & drop a batch file on the desktop that performed:
netsh winsock reset
restart the machine
The last part was required as the result of the first command severing my RDP connection or Lync\Skype For Business session.
A quick fix & a step closer to beer o'clock.