{'fraction_non_alphanumeric': 0.018136850783182192, 'fraction_numerical': 0.0, 'mean_word_length': 5.00990099009901, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A control theoretical analysis of a window-based flow control mechanism in TCP / IP networks

A window-based flow control mechanism is a sort of feedback-based congestion control mechanisms, and has been widely used in current TCP/IP networks. Recently proposed TCP Vegas is another version of the TCP mechanism and has potential to achieve much better performance than current TCP Tahoe and Reno. However, it has not been fully investigated how to determine control parameters of TCP Vegas. In this paper, we focus on a window-based flow control mechanism based on a congestion avoidance mechanism of TCP Vegas, and analyze its stability and transient behavior using a control theoretic approach. We show that the system stability is quite sensitive to the control parameter of the window-based flow control mechanism, and that its optimal value is particularly dependent on the end-to-end propagation delay. We also demonstrate that its performance can be dramatically improved by dynamically adjusting its control parameters based on our analytic results. We further investigate a buffer dimensioning issue at the router, and derive the condition for achieving full link utilization and preventing packet loss.