A host system is provided with one or more host-fabric adapters installed therein for connecting to a switched fabric of a data network. The host-fabric adapter may comprise at least one Micro-Engine arranged to establish connections and support data transfer operations, via a switched fabric, in response to work requests that cause instructions in a form of work queue elements "WQES" posted from a host system for said data transfer operations; and a work queue element "WQE" hardware assist "HWA" mechanism arranged to determine the starting address of each work queue element "WQE" based on queue pair (QP) context information needed for said Micro-Engine (ME) to process work requests for said data transfer operations.