TCP Delay-Friendliness

The performance of the Internet is dominated by that of the TCP which in turn depends that of its congestion control algorithm. The primary purpose of the TCP is to take care of the congestion collapse of Internet and also to act as resource optimization mechanism in best effort environment. However, this makes TCP to be unfriendly with real time applications for which UDP is preferred. There is no significant work existing in the literature to analyse the delay performance of TCP in the presence of other TCP flows to the best of our knowledge. This paper quantitatively analyses the effect of TCP flows on fellow TCP flows as well as on other UDP flows for end to end delay as the performance parameter. Extensive simulations using NS2 are conducted to validate the degradation in delay performance of TCP due to the increased fraction of TCP in the background traffic. The analysis also provides an analytical results to already known problem of TCP not able to provide stringent Quality-of-Service (QoS) as desired by delay sensitive applications. The issue now raises is whether the variants of TCP help desired Quality-of-Service for delay sensitive applications on Internet or a new-fangled approach is called for