Ethernet was developed by Robert Metcalfe at Xerox PARC in the early 70s and is a packet switching technology that uses Carrier Sense Mulit-access with Collision Detection ... Read More
Prior to 802.1q, switch vendors used proprietary methods to manage the transfer of VLAN tagged ethernet frames between switches. These methods added the vlan to the frame creating a proprietary frame. Otherwise the other switch would put the frame in the vlan it's port ... Read More