only implemented for para topo, for now.
example:
sudo ./mpPerf.py -t conf/topo/0_para_2 -x conf/xp/3_ncpv
after two seconds, delay goes to 100ms
after five seconds, delay goes to 2ms but loss rate goes to 10%
Signed-off-by: Benjamin Hesmans <benjamin.hesmans@uclouvain.be>
