TCP/NC: Stability and performance analysis with small buffer Drop-Tail queues
Santosh Chavan · 2016
Transmission control protocol (TCP) embedded with network coding (TCP/NC) has been proposed to improve the performance of TCP over wireless networks. Compound TCP is the default transport protocol in the Windows operating system. We analyze local stability, and performance of TCP/NC coexisting with Compound TCP in a bottleneck link with small buffer Drop-Tail queues. We develop a sufficient condition to show that, in networks running multiple TCP variants, parameters of any of the TCP variants can influence local stability. Further, the variation in parameters, such as buffer size, leads to loss of local stability, which gives rise to the onset of limit cycles in the queue size dynamics. Packet-level simulations conducted in the Network Simulator (NS2) exhibit limit cycles in the queue size. Our work, analytically and via simulations, highlights the importance of stability as a metric for performance evaluation.