Cabling is an increasingly important topic in the data center. This focus is growing with the proliferation of 10 Gb/s and 40 Gb/s cables in volume today, with 100 Gb/s cables already starting deployments, and with both intra-rack and inter-rack applications. Passive cabling provides a direct electrical connection between corresponding cable ends. Active cables provide the same effect but, by embedding optics and/or electronics within the connectors, can overcome some of the limitations of passive cables. While passive cables are always copper-based, active cables can use either copper wire or fiber optics to provide the link between the cable ends.