With the rapid progress of high-performance cluster applications, data transfer between clusters in distant locations becomes more important.But, it is difficult to transfer data using parallel TCP streams on long distance high bandwidth network. In this paper, we microscopically observe parallel TCP streams on 10Gbps network using our network analyzer, propose, implement, and evaluate ``Stream Equalizer'' which relaxes self-congestion and balances throughput among streams.We evaluate it using a real wide-area network over the Pacific Ocean.The network analyzer and the Stream Equalizer are implemented on FPGA-based programmable high-speed network testbed TGNLE-1.