SSthreshless Start: A Sender-Side TCP Intelligence for Long Fat Network

Measurement shows that 85% of TCP flows in the internet are short-lived flows that stay most of their operation in the TCP startup phase. However, many previous studies indicate that the traditional TCP Slow Start algorithm does not perform well, especially in long fat networks. Two obvious problems are known to impact the Slow Start performance, which are the blind initial setting of the Slow Start threshold and the aggressive increase of the probing rate during the startup phase regardless of the buffer sizes along the path. Current efforts focusing on tuning the Slow Start threshold and/or probing rate during the startup phase have not been considered very effective, which has prompted an investigation with a different approach. In this paper, we present a novel TCP startup method, called threshold-less slow start or SSthreshless Start, which does not need the Slow Start threshold to operate. Instead, SSthreshless Start uses the backlog status at bottleneck buffer to adaptively adjust probing rate which allows better seizing of the available bandwidth. Comparing to the traditional and other major modified startup methods, our simulation results show that SSthreshless Start achieves significant performance improvement during the startup phase. Moreover, SSthreshless Start scales well with a wide range of buffer size, propagation delay and network bandwidth. Besides, it shows excellent friendliness when operating simultaneously with the currently popular TCP NewReno connections.Comment: 25 pages, 10 figures, 7 table

Residual Capacity Estimator for TCP on wired/wireless links

Abstract: Having an inexpensive and accurate means to estimate capacity could be put in good use for several purposes: QoS schemes could utilize it to claim the feasible ratio at which video/audio streaming are allowed to transmit, bandwidth estimators could receive help in discriminating between their samples. In this paper, we present RCE (Residual Capacity Estimator), a new scheme able to provide a simple and effective esteem of the bottleneck link capacity deducted the uniformly distributed traffic present. Our scheme is embedded in the normal TCP functionalities and achieves precise results even from the very beginning of a connection. We provide simulation results under various and complex situations in order to prove the efficacy of RCE and we conclude with future directions for this work

Residual Capacity Estimator for TCP on wired/wireless links”, submitted at WCC2004-Student-Forum

Having an inexpensive and accurate means to estimate capacity could be put in good use for several purposes: QoS schemes could utilize it to claim the feasible ratio at which video/audio streaming are allowed to transmit, bandwidth estimators could receive help in discriminating between their samples. Nowadays, the plethora of applications available to users and the widely adopted mobile technology require new features that only an deeper awareness of the accessed link characteristics could provide. In this paper, we present RCE (Residual Capacity Estimator), a new scheme able to provide a simple and effective esteem of the bottleneck link capacity deducted the uniformly distributed traffic present. Our scheme is embedded in the normal TCP functionalities and achieves precise results even from the very beginning of a connection. We provide simulation results under various and complex situations in order to prove the efficacy of RCE and we conclude with future directions for this work