In managing and buffering packet data for transmission out of a host, descriptor ring data is pushed in from a host memory into a descriptor ring cache and cached therein. The descriptor ring data is processed to read a data packet descriptor, and a direct memory access is initiated to the host to read the data packet corresponding to the read data packet descriptor to a data transmission buffer. The data packet is written by the direct memory access into the data transmission buffer and cached therein. A return pointer is written to the host memory by the direct memory access indicating that the data packet descriptor has been read and the corresponding data packet has been transmitted. In managing and buffering packet data for transmission to a host, descriptor ring data is pushed in from a host memory into a descriptor ring cache and cached therein. Data packets for transmission to the host memory are received and cached in a data reception buffer. Data is read from the data reception buffer according to a data packet descriptor retrieved from the descriptor ring cache, and the data packet is written to a data reception queue within the host memory by a direct memory access. A return pointer is written to the host memory by the direct memory access indicating that the data packet has been written.