Catalyst 4000 Family Linecards are compatible with both the Catalyst 4500 Series and the Catalyst 4000 Series modular chassis. These linecards can be mixed and matched to suit a wide range of wiring closet, branch office, data center and metro Ethernet deployments. Catalyst 4000 Family linecards offer high-density connectivity and include copper and fiber-based interfaces for both Fast Ethernet and Gigabit Ethernet.