Dynamic transmit tuning for ethernet device drivers

摘要

A LAN of the ethernet type employs CSMA/CD protocol for channel access by a plurality of network nodes. Each node includes a data processing system having a device driver and an adapter and transmits data packets to the LAN in accordance with the IEEE 802.3 standard. The adapter coupled is at one side to the network in either a half or full-duplex mode. The other side of the adapter is bound to the device driver which is dynamically tuned for reduced latency and increased network throughput, regardless of the transmitting mode of the node and the capture effect of the ethernet. Each device driver operates in a transmit chaining mode when the network is in a lightly loaded half-duplex, or full-duplex mode. The driver includes device for monitoring data packet collisions on a channel of the network. A "collision rate" or the percentage of data packets which were transmitted on the channel with collisions in a pre-selected time interval is calculated by the device driver. A "collision threshold" is assigned or calculated by the device driver. Data packets transmitted by each device driver are chained to increase network throughput when the "collision rate" is below the "collision threshold". Transmit chaining of data packets is disabled for the device driver when the "collision threshold" is exceeded on the channel.