The ATM-fabric integration module seamlessly integrates the Catalyst 5500 switching fabric and the LightStream 1010 switching fabric in a Catalyst 5500 chassis. The ATM-fabric integration module installs in the Catalyst 5500 switch in slots 9 through 12 and bridges the 3.6-Gbps media-independent switch fabric and the 5-Gbps cell-switch fabric without the need for external cabling. The module also has one external OC-12 ATM port adapter interface.