An Improved TCP Vegas Model for Space Networks of the Bandwidth Asymmetry
Qixue Guan, Yueqiu Jiang · Intelligent Automation & Soft Computing · 2020
It is known that congestion in the reverse direction happens in advance of the congestion in the forward direction due to the significant bandwidth asymmetry in the two directions of the space networks, especially in the satellite networks, which enables the TCP Vegas to enter the phase of the congestion avoidance blindly and reduce the throughput of the forward direction. To solve this problem, a congestion control model, TCP Vegas-DDA, which maintains the frequency of the acknowledgments in the reverse direction is proposed. The model sets the interval time between acknowledgments dynamically based on the variation of the queuing delay in the reverse direction and reduces the impact of the queuing delay on the congestion control algorithm by amending the value of the base round-trip time. Results of the simulation indicate the problem of the low throughput in the forward direction caused by the congestion in the reverse direction can be solved, and the performance of the TCP Vegas in the asymmetric links can be improved.