Quality of service for TCP over satellite links in congested networks

In this paper, we demonstrate the unfair utilization of resources by transmission control protocol (TCP) traffic flows traversing satellite links when they compete with terrestrial flows in a congested router. To mitigate this problem and provide quality of service (QoS), we propose a preferential suppression (PS) scheme to suppress flows that consume too many resources. By selectively suppressing terrestrial TCP flows with PS, we show that resources can be allocated fairly to the TCP flows using satellite links. However, these TCP flows cannot fully utilize available bandwidth due to the long delay in receiving feedback over high latency satellite links. To improve response time, a TCP spoofing scheme is integrated with PS to reduce the effective round-trip time. Simulation results show that target TCP flows are able to utilize a designated amount of bandwidth and, thus, can achieve QoS objectives. This enables QoS support in an edge router for TCP flows over satellite links that must compete with other flows in the terrestrial network.