<P> The SuperStack II Switch 1100/3300 ATM expansion module is the industry s first OC-3c/OC-12c ATM downlink. The SuperStack II Switch 1100/3300 ATM expansion module is based on 3Com s revolutionary ZipChip 3 ASIC, a high-performance policy-enabled, multilayer switching engine capable of wire-speed forwarding at Layer 2 and Layer 3. Designed to meet the challenge of increasing workgroup demands, the SuperStack II Switch 1100/3300 ATM expansion module provides a flexible-speed ATM port for connection to a multiservice backbone network. The ATM port is software configurable to run at either OC-3c (155 Mbps) or high-bandwidth OC-12c (622 Mbps) speeds, providing a clear migration path for peak investment protection. </P>