does '-n' work?
Seems like with '-n' iperf (1.65, Linux) is sending 2 packets, whatever
is '-n' set to, and reports it sent 1:
[root --at-- yogi bin]# iperf -c 10.9.201.5 -u -n 1 -l 14
------------------------------------------------------------
Client connecting to 10.9.201.5, UDP port 5001
Sending 14 byte datagrams
UDP buffer size: 64.0 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.9.121 port 32778 connected with 10.9.201.5 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 0.0 sec 14.0 Bytes 1.87 Mbits/sec
[ 3] Sent 1 datagrams
[root --at-- yogi bin]# iperf -c 10.9.201.5 -u -n 2 -l 14
------------------------------------------------------------
Client connecting to 10.9.201.5, UDP port 5001
Sending 14 byte datagrams
UDP buffer size: 64.0 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.9.121 port 32778 connected with 10.9.201.5 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 0.0 sec 14.0 Bytes 1.90 Mbits/sec
[ 3] Sent 1 datagrams
[root --at-- yogi bin]# iperf -c 10.9.201.5 -u -n 4 -l 14
------------------------------------------------------------
Client connecting to 10.9.201.5, UDP port 5001
Sending 14 byte datagrams
UDP buffer size: 64.0 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.9.121 port 32778 connected with 10.9.201.5 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 0.0 sec 14.0 Bytes 1.84 Mbits/sec
[ 3] Sent 1 datagrams