Movies from SMB shares hangs often

[DBMandrake]

What kind of switch is your Pi and Server plugged into ?

Does this help ?

Bad video performance on Pi 3

Is your Cisco switch a managed switch ? (EG has a web interface or configuration utility) If so check to see if flow control is enabled on the ports. If not try enabling it. Alternatively try adding smsc95xx.turbo_mode=Y to the end of the line in /boot/cmdline.txt then rebooting.