The 40 Gigabit data center TOR wiring mode is to use a standard 42U server cabinet, and then put a 40 Gigabit switch above the server cabinet. The server in the server cabinet is connected to the switch at the upper end through the 40 Gigabit DAC direct attach cable, and finally connect the switch on the upper cabinet to the convergence layer / core layer switch.

Due to the large number of ports of fiber optic switch, in order to avoid port redundancy, so the number of server cabinet is relatively dense, and generally 42U standard server cabinet will be used. However, 42U standard cabinet doesn’t mean that 42 pieces of 1U servers, because the cabinet will consider reserved heat and move space, power supply and other factors, as well as the cabinet need to have space for walking the line to empty place, placing the switch, the firewall and other equipment. So usually under the 42U standard cabinet, you can place about 20 pieces of 1U servers.

The length of the 40G DAC high-speed cable is within 5 meters, which is more than enough in the 40G data center TOR wiring, because the 42U server cabinet is only 2 meters high.

When the optical port of the server connects the 40 Gigabit switch, the 40G server network card should be inserted into the PCI-E bus interface, and then the module at one end of the 40 Gigabit DAC high speed cable is connected to the server network card and the other end to the 40 Gigabit switch. Finally, the uplink port on the top level of the server is connected to the convergence layer / core layer switch.

The length of the 40G DAC high-speed cable is within 5 meters, which is more than enough in the 40G data center TOR wiring, because the 42U server cabinet is only 2 meters high.

Generally, due to cost-effective factors, DAC TOR wiring uses the DAC high-speed cable.