Thanks for the reply's.  The communication driver installed was from Microsoft and was loaded with Window 10. Although Window 10 and the "Dell Update" reported all the drivers were up to date, I reluctantly installed the latest Driver from Broadcom (NetLink® 57xx (x64) Version 15.6.0.10). Problem solved.  As a test, several times today i simultaneously connected to more than 6 websites with at least 3 running videos without any connectivity issues.  
After upgrading to Windows 10 Pro 64bit on my Studio XPS 8100 I am losing internet connectivity when there are several websites open in a browser (tried several). With normal web activity all seems ok. To restore the connection which completely disappears I unplug and then reconnect the Ethernet cable, then enable the “Local Area Connection” Broadcom NetLink network device. The Dell Update software believes I have the latest drivers. Thank you  
Windows 10 internet connection lost with heavy use