problem with -l options in UDP mode

["Valery V. Bobrov" <vb --at-- uvttk.ru>]

Hello!

I faced the following problrem when I was trying to use iperf with -l and -u
options.

I try to run iperf as
iperf -s  -u -i 1

and I saw the following
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 8.00 KByte (default)
------------------------------------------------------------
there is phrase in the docs "Default is 8 KB for TCP, 1470 bytes for UDP."

Is the information above correct?

I read the following "To measure packet loss instead of datagram loss, make
the datagrams small enough to fit into a single packet, using the -l option.
"

How can I do it?

Yours sincerely,
     Valery