Abstract
The default acknowledgment (ACK) strategy of TCP easily overruns the constrained ACK channel capacity of the asymmetric network links. There is no effective ACK mechanism to address the asymmetric channel problem for space-Internet. A configurable ACK delay (CAD) mechanism has been developed to delay the ACKs for a configurable period of time to improve the TCP throughput performance over asymmetric space-Internet links. This paper introduces the CAD mechanism and presents a performance evaluation of it in an experimental manner. The experimental results show that the CAD mechanism has significant performance advantages in asymmetric space links with a channel ratio higher than 50/1. The higher the asymmetric channel ratio is, the more advantageous the CAD is over the default ACK strategy.