An architecture and NIC (Network Interface Card) for coupling Data Processing Equipment to a communications network includes a host memory having a High Priority Queue storing control information and data, a Low Priority Queue storing control information and data. Control registers, in the NIC, store addresses identifying the location of said Queues and a block size register, in the NIC, stores a value representing the size of data blocks to be transferred from the host memory to the NIC. A controller transfers allowable block size data from the host memory to buffers on said NIC.