Multi-port device used to connect a quasi-exclusive 10/100/1000 Mbps connection between any two-end systems using the source and destination addresses of the packet via the internal bus. Switches work at the MAC (Media Access Control) Layer and above and use either "store and forward" or "cut-through" technology. Switches are "plug-and-play " devices that can be used to segment a network when it starts to slow down. Each port can function at the rated speed of the switch and some are auto-sensing for 10/100 Mbps. Ethernet switches are offered as standalone systems or as modules for existing hubs.