Previous delay-based congestion control algorithms always omit the impact of traffic in reverse path, e.g. TCP Vegas. To address this problem, we analyze the relation between TCP performance and reverse traffic and describe a novel approach, Unidirectional Trip Aware TCP, UTA TCP, for congestion control in high-speed long-latency networks, from design to implementation. Results of our experiments show that UTA TCP outperforms those conventional delay-based congestion control algorithms.