Delay-insensitive applications, such as P2P file sharing, generate substantial amounts of traffic and compete with other applications on an equal footing when using TCP. Further, to optimize throughput, such applications open multiple connections. This results in an unfair and potentially poor service for other applications having stringent performance objectives. In this paper, we propose NF-TCP, a TCP variant for P2P and similar background delay-insensitive applications. NF-TCP aims to be submissive to delay-sensitive applications under congestion. It is designed to be network friendly based on a fluid flow model for intermediate queues and uses explicit congestion notification (ECN) for early detection of congestion. Moreover, it exploits the measure of the available bandwidth to be able to aggressively utilize spare capacity. We implemented NF-TCP on Linux and ns-2. Our evaluations of the NF-TCP Linux implementation on ns-2 show that NF-TCP outperforms other network friendly approaches (e.g., LEDBAT, TCP-LP and RAPID). NF-TCP achieves high utilization, fair bandwidth allocation among NF-TCP flows and maintains a small average queue. Our evaluations further demonstrate that with NF-TCP, the available bandwidth can be efficiently utilized for supporting both delay-sensitive and insensitive traffic in a wide range of scenarios.
NF-TCP REF , a network-friendly TCP for delay insensitive applications, uses chirping congestion control.
NF-TCP: A Network Friendly TCP Variant for Background Delay-Insensitive Applications
Networking
Computer Science Engineering