Throughput improvement for Ethernet over USB

When embedded devices are connected by USB bus, it is convenient to use Ethernet emulation model which can be used for conventional TCP/IP network. USB Communication Data Class (CDC) defines Ethernet over USB protocol which can be implemented by emulation protocol software, but when it is used with real system, it shows performance degradation problems especially for small size latency critical data. In this paper, we have suggested three improvements. One is bundling multiple network frames into single USB transfer, the other is parallel queuing packet transmission requests, and the third is network jumbo frames. After applying above three items together, it results in 50% improvements in throughput.