Window flow control on a byte-stream virtual circuit with processor- sharing nodes.

In the sliding-window protocol for data transmission, a number of frames bearing consecutive sequence numbers are transmitted and then the sender waits to transmit each following frame until the appropriate sequential acknowledgement has been returned. We study the throughput vs. window-size behavior of the sliding- window protocol on a multihop byte-stream virtual circuit where the node service discipline is processor sharing, background traffic is Poisson with exponentially distributed message lengths, and propagation times are a significant fraction of the total delay. Analytic models are compared with the results of simulation. For small windows, the throughput is controlled by the ratio of window size to round-trip propagation time. For large windows, the throughput is controlled by the background traffic level and the ratio of window size to background message length.