Smoothing the XCP sender

It is known fact that modern IP networks are adopting eXplicit Control Protocol (XCP) as the de-facto standard. In the implementation of XCP, the XCP sender outputs packets in bursts such that all the packets inside the congestion window are outputted without any interval between them. The burst not only increases the queuing delay, but also makes XCP with heterogeneous delays to be unstable. In the present paper, a Smooth XCP (SXCP) is proposed, where the interval of outputting packets at the XCP sender is no less than the round trip time divided by the congestion window. The simulations show that SXCP not only decreases the queuing delay, but also improves utilization and stability.