Is UDP connection capped at 1.05 Mbit/sec?

We tested transferring data to one of our servers via UDP and here is the result:

./iperf3 -c --udp Connecting to host, port 5201 [ 4] local port 52877 connected to port 5201 [ ID] Interval Transfer Bandwidth Total Datagrams [ 4] 0.00-1.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 1.00-2.01 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 2.01-3.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 3.00-4.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 4.00-5.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 5.00-6.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 6.00-7.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 7.00-8.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 8.00-9.00 sec 128 KBytes 1.05 Mbits/sec 16 [ 4] 9.00-10.00 sec 128 KBytes 1.05 Mbits/sec 16

[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 4] 0.00-10.00 sec 1.25 MBytes 1.05 Mbits/sec 59.160 ms 0/159 (0%)

Can someone help us make sense out of this? Same test done over TCP gives a speed of 170 Mbits/sec…


Submit an answer

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Sign In or Sign Up to Answer

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Site Moderator
Site Moderator badge
March 10, 2023
Accepted Answer

Hey @cronchi,

That’s really strange, the only limits that should be exeprienced are here:

Can you see if you are still experiencing this? Is it possible the cap is also coming from your network? I’ll still ask around to see if there is any UDP cap.

This comment has been deleted

    The default

    iperf3 -c hostname --udp

    is only capped to 1Mbps

    if you want to test with more bandwidth, add -b <bandwidth> argument to the command

    iperf3 -c hostname --udp -b 100M

    to test with 100Mbps Bandwidth

    Try DigitalOcean for free

    Click below to sign up and get $200 of credit to try our products over 60 days!

    Sign up

    Featured on Community

    Get our biweekly newsletter

    Sign up for Infrastructure as a Newsletter.

    Hollie's Hub for Good

    Working on improving health and education, reducing inequality, and spurring economic growth? We'd like to help.

    Become a contributor

    Get paid to write technical tutorials and select a tech-focused charity to receive a matching donation.

    Welcome to the developer cloud

    DigitalOcean makes it simple to launch in the cloud and scale up as you grow — whether you're running one virtual machine or ten thousand.

    Learn more
    DigitalOcean Cloud Control Panel