Title: Why is the Internet traffic bursty in short (sub-RTT) 
time scales?

Internet traffic exhibits multifaceted burstiness and 
correlation structure over a wide span of time scales. 
Previous work analyzed this structure in terms of heavy-
tailed session characteristics, as well as TCP timeouts and 
congestion avoidance, in relatively long time scales.

We focus on shorter scales, typically less than 100-1000 
milliseconds. Our objective is to identify the actual 
mechanisms that are responsible for creating bursty traffic 
in those scales. We show that TCP self-clocking, joint with 
queueing in the network, can shape the packet interarrivals 
of a TCP connection in a two-level ON-OFF pattern. 

This structure creates strong correlations and burstiness in 
time scales that extend up to the Round-Trip Time (RTT) of 
the connection, especially for bulk transfers that have a 
large bandwidth-delay product relative to their window size. 
The burstiness in short scales can be significantly reduced 
by TCP pacing. 

In particular, we focus on the importance of the minimum 
pacing timer, and show that a 10-millisecond timer would be 
too coarse for removing short-scale traffic burstiness, 
while a 1-millisecond timer would be sufficient to make the 
traffic almost as smooth as a Poisson stream. Finally, we 
show that sub-RTT burstiness is important in queueing 
performance not only in moderate load conditions, as 
previously shown, but also in high loads when the bottleneck 
buffer size is relatively small.