Please don't drop the group when you reply.
The bandwidth of the links needs to be defined when you build your mininet topology, e.g.
sudo mn --custom sflow-rt/extras/sflow.py --link tc,bw=10 \
--topo tree,depth=4,fanout=2
The above example sets the bandwidth to 10 Mbit/s. Unfortunately, the tc bandwidth limit isn't visible to Open vSwitch, so it is incorrectly reported in the sFlow feed. However, it isn't hard to look at the reported bit/s charts in the dashboard and convert to utilization since you know the configured effective bandwidth.
I try it but it did not give the information I need like the bandwidth of each link in topology