Real-time transmission over asymmetric satellite IP links is challenging, since satellite systems commonly exhibit long propagation delays, while bandwidth asymmetry often enforces a variable and infrequent rate of acknowledgment packets (ACKs) across the upstream channel with several undesirable implications. In this context, we formulate an analytical model in order to quantify the impact of satellite systems and link asymmetry on TCP performance and real-time delivery. We emphasize on the effects of asymmetric links, and especially on the implications that cause interruptions in the sending rate, and eventually disturb smooth delivery. Since TCP performance is in part throttled by the rate of arriving ACKs, we additionally investigate the impact of delayed ACKs. Although delayed ACKs occasionally diminish the transmission rate, we uncover notable gains in terms of smoothness and real-time delivery. Furthermore, we demonstrate conclusive performance studies tackling the supportive ...