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Flow optimization and data compression methods promise to improve TCP performance, and edge devices that implement them to transparently improve wide-area network performance are currently being developed. We present an experimental study of TCP throughput performance of such Cisco devices using 1 Gbps connections of thousands of miles over UltraScience Net. Based on iperf measurements, we have the following observations: (i) multi-fold throughput improvements are achieved over the buffer-tuned TCP both for single and most multiple streams; and (ii) high throughputs are maintained over connection lengths of thousands of miles. For file transfers using iperf, our experiments included files with repeated bytes and uniformly randomly generated bytes, and supernova simulation data in hdf format: (i) highest and lowest throughputs are achieved for hdf and random data files, respectively; (ii) most throughputs were maximized by 5-10 parallel TCP streams; and (iii) pre-compression of files using gzip did not have a significant effect on transport performance.