The 3Com Switch 4007 offers the simplicity of a backbone-in-a-box, high-speed LAN solution to meet the needs of today's commercial businesses. With 3Com's Switch 4007 your business can support new applications, provide guaranteed network availability and help ensure access to the network from anywhere. The chassis ID printed circuit board (PCB) for the CoreBuilder 9000 Enterprise Switch 16-slot chassis or 7-slot chassis is a serial EEPROM that contains the chassis ID information and a temperature sensor. This ID PCB is mounted on a PCB assembly component that connects to a 14-pin DIP socket at the top of the backplane inside the chassis