Steady State Analysis of TCP Connections with Different Propagation Delays

In the current Internet, most of the traffic is transmitted by TCP (Transmission Control Protocol). In [1], we have proposed a modeling approach for the entire network, including TCP congestion control mechansims operating at source hosts and the network seen by TCP connections, as a single feedback system. However, in [1], our analytic model is limited to a simple network, where TCP connections have the identical propagation delay. In this paper, we therefore extend the analytic approach proposed in [1] to a more generic network, where multiple TCP connections are allowed to have different propagation delays. We derive the packet loss probability in the network, throughput and average round-trip time of each TCP connection in steady state. By showing several numerical examples, we quantitatively investigate how the fairness among TCP connections is degraded when multiple TCP connections with different propagation delays share the single bottleneck link.