1Universidade Federal de Pernambuco – UFPE Caixa Postal 7851 – 50732-970 – Recife – PE 2Centro Federal de Educação Tecnológica de Alagoas – CEFET-AL

Abstract. Standard TCP congestion control mechanisms degrade performance of small flows, especially during the Slow Start phase, which often causes multiple packet losses. We propose a modified TCP startup mechanism, called Burst TCP (B-TCP), which employs a responsive growth scheme based on current window size, to improve performance for small flows. Our simulation experiments, considering heavy-tailed traffic, show that B-TCP can significantly reduce both transfer times and packet losses for small flows without causing damage to large flows. Additionally, B-TCP is easy to implement and requires TCP adjustment at the sender side only. 1