Low UDP iperf throughput

[ariel.dalessandro]

Hi all,

I'm running the esp-idf iperf example [0] and the maximum UDP throughput is ~1.05Mbits/sec, but according to the docs [1] it should be ~30Mbits/sec.

Is really 30Mbits/sec the expected throughput on this scenario?

Target hardware:

* ESP32 Core Board V2.

Test setup:

* testing on esp-idf tag v3.2 [2] and commit 05838641 [3], as suggested in [1]. Same results on both versions.
* using config examples/wifi/iperf/sdkconfig.defaults.99 [4] as suggested here [1].
* testing using ESP32 in AP and STA modes. Same results on both versions.

Test log:

* ESP32 (iperf server):

Code: Untitled.bsh Select all

esp32> iperf -s -u -i 1 -t 10

I (847313) cmd_wifi: mode=udp-server sip=192.168.1.105:5001, dip=0.0.0.0:5001, interval=1, time=10

I (847326) iperf: want recv=16384

        Interval Bandwidth

   0-   1 sec       0.62 Mbits/sec

   1-   2 sec       1.05 Mbits/sec

   2-   3 sec       1.05 Mbits/sec

   3-   4 sec       1.06 Mbits/sec

   4-   5 sec       1.05 Mbits/sec

   5-   6 sec       1.05 Mbits/sec

   6-   7 sec       1.05 Mbits/sec

   7-   8 sec       1.02 Mbits/sec

   8-   9 sec       1.07 Mbits/sec

   9-  10 sec       1.06 Mbits/sec

   0-  10 sec       1.01 Mbits/sec

I (857338) iperf: iperf exit

esp32>

*Linux host (iperf client):

Code: Untitled.bsh Select all

$ iperf -c 192.168.1.105 -i 1 -t 10 -u -e 

------------------------------------------------------------

Client connecting to 192.168.1.105, UDP port 5001 with pid 13039

Sending 1470 byte datagrams, IPG target: 11215.21 us (kalman adjust)

UDP buffer size:  208 KByte (default)

------------------------------------------------------------

[  3] local 192.168.0.101 port 34857 connected with 192.168.1.105 port 5001

[ ID] Interval            Transfer     Bandwidth      Write/Err  PPS

[  3] 0.0000-1.0000 sec   131 KBytes  1.07 Mbits/sec  91/0       90 pps

[  3] 1.0000-2.0000 sec   128 KBytes  1.05 Mbits/sec  89/0       89 pps

[  3] 2.0000-3.0000 sec   128 KBytes  1.05 Mbits/sec  89/0       89 pps

[  3] 3.0000-4.0000 sec   128 KBytes  1.05 Mbits/sec  89/0       89 pps

[  3] 4.0000-5.0000 sec   128 KBytes  1.05 Mbits/sec  89/0       89 pps

[  3] 5.0000-6.0000 sec   128 KBytes  1.05 Mbits/sec  89/0       89 pps

[  3] 6.0000-7.0000 sec   129 KBytes  1.06 Mbits/sec  90/0       89 pps

[  3] 7.0000-8.0000 sec   128 KBytes  1.05 Mbits/sec  89/0       89 pps

[  3] 8.0000-9.0000 sec   128 KBytes  1.05 Mbits/sec  89/0       89 pps

read failed: Connection refused

[  3] WARNING: did not receive ack of last datagram after 2 tries.

[  3] 0.0000-10.0041 sec  1.25 MBytes  1.05 Mbits/sec  892/16       89 pps

[  3] Sent 892 datagrams

$

Thanks in advance,
Ariel

[0]: https://github.com/espressif/esp-idf/tr ... wifi/iperf
[1]: https://docs.espressif.com/projects/esp ... throughput
[2]: https://github.com/espressif/esp-idf/releases/tag/v3.2
[3]: https://github.com/espressif/esp-idf/commit/05838641
[4]: https://github.com/espressif/esp-idf/bl ... efaults.99

[Angus]

Hi Ariel,

The main difference is that the 30Mbit/sec is measured in a shielded box - so strong WiFi signal and no interference.

Can you give any information about the WiFi signal where you were testing?

[ariel.dalessandro]

Hi ESP_Angus,
Thanks for the quick reply.

The main difference is that the 30Mbit/sec is measured in a shielded box - so strong WiFi signal and no interference.

Is it? According to https://docs.espressif.com/projects/esp ... throughput:
* Espressif’s lab Rx/Tx = 30/30Mbit/sec.
* Shield box Rx/Tx = 90/60Mbit/sec.

Can you give any information about the WiFi signal where you were testing?

Yes. Using ESP32 in AP mode (ssid: esp32test):

Code: Untitled.bsh Select all

$ nmcli device wifi list 

IN-USE  SSID                      MODE   CHAN  RATE        SIGNAL  BARS  SECURITY  

*       esp32test                 Infra  2     135 Mbit/s  100     ▂▄▆█  WPA1 WPA2 

        FS2.4                     Infra  1     195 Mbit/s  69      ▂▄▆_  WPA1 WPA2 

        FiberCorp WiFi742 2.4GHz  Infra  6     195 Mbit/s  59      ▂▄▆_  WPA1 WPA2 

        WiFi-3A                   Infra  6     135 Mbit/s  59      ▂▄▆_  WPA1 WPA2 

        WNinternet_A3B20          Infra  9     130 Mbit/s  49      ▂▄__  WPA2      

        Bertita1                  Infra  1     130 Mbit/s  40      ▂▄__  WPA1 WPA2 

        AndroidAP                 Infra  11    130 Mbit/s  40      ▂▄__  WPA2      

        WIFI-891-Local            Infra  6     54 Mbit/s   35      ▂▄__  WPA2      

        Riccobelli                Infra  6     54 Mbit/s   35      ▂▄__  WPA1 WPA2 

        DIRECT-t7M2020 Series     Infra  6     54 Mbit/s   35      ▂▄__  WPA2      

        AnyCast-D977D467          Infra  11    135 Mbit/s  35      ▂▄__  WPA2      

        Diavoli rossi             Infra  11    65 Mbit/s   35      ▂▄__  WPA2      

        FS5.8                     Infra  52    405 Mbit/s  35      ▂▄__  WPA1 WPA2 

        FiberCorp WiFi742 5.8GHz  Infra  153   405 Mbit/s  35      ▂▄__  WPA1 WPA2 

        Fibertel WiFi228 2.4GHz   Infra  6     195 Mbit/s  34      ▂▄__  WPA1 WPA2 

        pepavik                   Infra  1     195 Mbit/s  32      ▂▄__  WPA1 WPA2 

        WiFi-Arnet-B7990F         Infra  11    270 Mbit/s  29      ▂___  WPA2      

        Fibertel WiFi885 2.4GHz   Infra  11    130 Mbit/s  29      ▂___  WPA1 WPA2 

[ariel.dalessandro]

Hi all,

Any further thoughts on this?

I'd like to extend the initial post as I don't think this is WiFi signal or interference problem.
I'm getting 30Mbps -matching the "lab" results- for all possible configurations, except for ESP32 in UDP server mode (see Test 2 below).

The following tests were performed using the same test setup as in the original post.

Test 0: iperf TCP
ESP32 server - Linux client

Code: Untitled.bsh Select all

        ESP32 server:

                esp32> iperf -s



        Linux client:

                $ iperf -c 192.168.4.1 -i 1 -t 5

                ------------------------------------------------------------

                Client connecting to 192.168.4.1, TCP port 5001

                TCP window size:  178 KByte (default)

                ------------------------------------------------------------

                [  3] local 192.168.4.2 port 33534 connected with 192.168.4.1 port 5001

                [ ID] Interval       Transfer     Bandwidth

                [  3]  0.0- 1.0 sec  6.12 MBytes  51.4 Mbits/sec

                [  3]  1.0- 2.0 sec  4.25 MBytes  35.7 Mbits/sec

                [  3]  2.0- 3.0 sec  6.00 MBytes  50.3 Mbits/sec

                [  3]  3.0- 4.0 sec  6.12 MBytes  51.4 Mbits/sec

                [  3]  4.0- 5.0 sec  5.50 MBytes  46.1 Mbits/sec

                [  3]  0.0- 5.0 sec  28.0 MBytes  47.0 Mbits/sec

Test 1: iperf TCP
Linux server - ESP32 client

Code: Untitled.bsh Select all

        Linux server:

                $ iperf -s



        ESP32 client:

                esp32> iperf -c 192.168.4.2 -i 1 -t 5

                I (199664) cmd_wifi: mode=tcp-client sip=192.168.4.1:5001, dip=192.168.4.2:5001, interval=1, time=5

                        Interval Bandwidth

                   0-   1 sec       33.82 Mbits/sec

                   1-   2 sec       42.21 Mbits/sec

                   2-   3 sec       4.98 Mbits/sec

                   3-   4 sec       24.51 Mbits/sec

                   4-   5 sec       50.33 Mbits/sec

                   0-   5 sec       31.17 Mbits/sec

                I (204790) iperf: iperf exit

Test 2: iperf UDP
ESP32 server - Linux client

Code: Untitled.bsh Select all

        ESP32 server:

                esp32> iperf -s -u



        Linux client:

                $ iperf -c 192.168.4.1 -i 1 -t 5 -u

                ------------------------------------------------------------

                Client connecting to 192.168.4.1, UDP port 5001

                Sending 1470 byte datagrams, IPG target: 11215.21 us (kalman adjust)

                UDP buffer size:  208 KByte (default)

                ------------------------------------------------------------

                [  3] local 192.168.4.2 port 34986 connected with 192.168.4.1 port 5001

                [ ID] Interval       Transfer     Bandwidth

                [  3]  0.0- 1.0 sec   131 KBytes  1.07 Mbits/sec

                [  3]  1.0- 2.0 sec   128 KBytes  1.05 Mbits/sec

                [  3]  2.0- 3.0 sec   128 KBytes  1.05 Mbits/sec

                [  3]  3.0- 4.0 sec   128 KBytes  1.05 Mbits/sec

                [  3] WARNING: did not receive ack of last datagram after 10 tries.

                [  3]  0.0- 5.0 sec   640 KBytes  1.05 Mbits/sec

                [  3] Sent 446 datagrams

Test 3: iperf UDP
Linux server - ESP32 client

Code: Untitled.bsh Select all

        Linux server:

                $ iperf -s -u



        ESP32 client:

                esp32> iperf -c 192.168.4.2 -i 1 -t 5 -u

                I (314567) cmd_wifi: mode=udp-client sip=192.168.4.1:5001, dip=192.168.4.2:5001, interval=1, time=5

                        Interval Bandwidth

                   0-   1 sec       30.44 Mbits/sec

                   1-   2 sec       52.96 Mbits/sec

                   2-   3 sec       55.55 Mbits/sec

                   3-   4 sec       57.15 Mbits/sec

                   4-   5 sec       58.94 Mbits/sec

                   0-   5 sec       51.01 Mbits/sec

                I (319581) iperf: iperf exit

Thanks,
Ariel

[WiFive]

Try

Code: Select all

iperf -b 30M -u -c 192.168.4.1