The Switch Fabric Module is the core of the 3Com Switch 8800 system. The Switch Fabric performs route calculation and provides all Layer 3 switching functionality. It also performs Layer 2 switching between interface modules and where on-board Layer 2 switching is not possible.

Based on the address-forwarding table, the hardware performs line-speed switching of Layer 2 / Layer 3 data packets. VLANs, link aggregation, QoS traffic classification and prioritization, and ACLs (Access Control Lists) are also supported by the hardware.

In addition to switching functions, the Switch Fabric Module performs control and management functions for the system. The management channel performs such functions as initialization and configuration of the system, data packet learning, protocol processing, and network management. It also provides environmental monitoring, software upgrade and interface module control.

When a second fabric is installed in a Switch 8800, both switch fabrics are active, in essence doubling the performance of a switch compared to having just a single switch fabric; in addition, fabric resiliency is provided.