Reordering of packets is not very common in networks, and the delay
functions will always introduce reordering if delay > packet-spacing,
so by setting allow-reordering to FALSE you guarantee that the packets
are in order, while at the same time introducing delay/jitter to them.
By using the property "delay-distribution" the user can control how the
delay applied to delayed packets is distributed. This is either the
uniform distribution (as before) or the normal distribution.
"min-delay" and "max-delay" control both distributions. For the normal
distribution it defines the bounds of the 95% confidence interval.
