perfSONAR User Q&A and Other Discussion

Hi all,
I have install perfSONAR-PS perfSONAR-BUOY. I test bwctld by command 
line(service bwctld start) and bwctld have start (/etc/init.d/bwctld start: 
bwctld (pid 12385) already running).
When I use bwctl's tool iperf incommand line (bwctl -T iperf -s) and in the 
other window (bwctl -T iperf -c 127.0.0.1),the client window shown the 
message "bwctl: Requested tool "iperf" not supported by both servers. See the 
'-T' option bwctl: Available in-common: thrulay" , why cann't I use the tool 
iperf ? How can I use bwctl's tool iperf in command line?