Cisco Catalyst 6500 series mixed media/fiber-based gigabit Ethernet interface modules are used in distribution and core layers, and in data-center applications. These gigabit Ethernet interface modules deliver wire-speed switched connectivity and support several switch fabric connections and traffic forwarding options, these include: Classic, CEF256, dCEF256 and CEF720. With a range of port densities and modular physical layer interfaces, these modules also offer a choice of packet buffer depths for traffic shaping, and QoS granularity with varying number of queues and drop threshold options. These key features are important aspects to in determining best module for a given network application.