Why is my UDP so slow?

Solution 1:

iPerf uses a default of 1Mb/sec for UDP tests. Use the -b flag on the iperf client to specify the UDP bandwidth you want to transmit at e.g.

iperf -c 10.79.175.219 -u -f m -b 100M

Solution 2:

As Nick answered, iPerf uses a default of 1Mbit/sec for UDP.

In order to use the same bandwidth as TCP while performing a UDP test, simply provide -b flag with the value of 0.

iperf3 --udp -b 0 -f m -c <server ip>

form the documentation,

-b, --bandwidth #[KMG][/#]
target bandwidth in bits/sec

(0 for unlimited)

(default 1 Mbit/sec for UDP, unlimited for TCP)

(optional slash and packet count for burst mode)

-f in the above command provide type of formatting (m if for MBits),

-f, --format [kmgKMG] format to report: Kbits, Mbits, KBytes, MBytes