One of the harder things to make a transport protocol deal with is
compressed acks. Thats where a channel access time will be hit, during
which packets are queued. When the channel is accessed some time
later (think up to 200ms) all of the packets that were queued are
released. This causes a series of acks that used to be spaced out
to arrive all at once.
In order to "fix" a protocol to better work with compressed acks one
needs a mechanism to simulate it. This set of changes to dummynet allows
that by adding two new features to the profile configuration of dummynet.