The Catalyst 8510 MSR/LightStream 1010 ATM Router Module (ARM) provides high-speed interworking between the Asynchronous Transfer Mode (ATM) and Layer 3 environment interfaces in a single chassis. The ARM is supported by the Catalyst 8510 MSR and LightStream 1010 platforms, providing large enterprises and service providers with a wide range of Layer 3 and ATM interfaces for building integrated solutions.The ATM Router Module features Cisco Express Forwarding (CEF), a new paradigm for route distribution and forwarding by distributing routing information from the central processor to the individual interface modules. Used within the Internet, this technology provides for scalability in large campus core networks. CEF provides Layer 3 forwarding based on a "shadow" of the routing table, resulting in very-high-speed routing table lookups and forwarding. This feature provides for wire-speed IP and IPX switching. The ARM is unique in that it allows Layer 3 traffic to pass seamlessly between ATM and Layer 3 interfaces. The benefit to the customer is that wire-speed Layer 3 switching between frame (Gigabit Ethernet/Fast Ethernet) ports, ATM switching between ATM ports, and high-speed frame/ATM interworking are combined in a single chassis. The result is fewer products in the network, simplified network designs, and a lower total cost of ownership.