Cisco offers a variety of connectivity, expansion and upgrade modules and cards to accommodate the customer specific needs. Cisco's components can help you easily build your own network according to your needs. Cisco offers this 48-port, field-upgradeable fabric-enabled 10/100 RJ-21 Module for the Catalyst 6500 Series Switches, designed to support Distributed Cisco Express Forwarding (dCEF) for maximum scalability.