# Ethernet iperf Example
(See the README.md file in the upper level 'examples' directory for more information about examples.)
## Overview
This example demonstrates basic usage of [iperf](https://iperf.fr/) protocol to measure the throughout/bandwidth of Ethernet.
The cli environment in the example is based on the [console component](https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/console.html).
## How to use example
### Hardware Required
To run this example, it's recommended that you have an official ESP32 Ethernet development board - [ESP32-Ethernet-Kit](https://docs.espressif.com/projects/esp-idf/en/latest/hw-reference/get-started-ethernet-kit.html). This example should also work for 3rd party ESP32 board as long as it's integrated with a supported Ethernet PHY chip. Up until now, ESP-IDF supports up to four Ethernet PHY: `LAN8720`, `IP101`, `DP83848` and `RTL8201`, additional PHY drivers should be implemented by users themselves.
Besides that, `esp_eth` component can drive third-party Ethernet module which integrates MAC and PHY and provides common communication interface (e.g. SPI, USB, etc). This example will take the **DM9051** as an example, illustrating how to install the Ethernet driver in the same manner.
#### Pin Assignment
See common pin assignments for Ethernet examples from [upper level](../README.md#common-pin-assignments).
### Software Tools Preparation
1. Install iperf tool on PC
* Debian/Ubuntu: `sudo apt-get install iperf`
* macOS: `brew install iperf`(if using Homebrew) or `sudo port install iperf`(if using MacPorts)
* Windows(MSYS2): Downloads binaries from [here]( https://iperf.fr/iperf-download.php#windows)
### Configure the project
```
idf.py menuconfig
```
In addition to the common configurations for Ethernet examples from [upper level](../README.md#common-configurations), you might also need to update the default value of following configurations:
1. In the `Example Configuration` menu:
* Enable storing history commands in flash under `Store command history in flash`.
### Build, Flash, and Run
Build the project and flash it to the board, then run monitor tool to view serial output:
```
idf.py -p PORT build flash monitor
```
(Replace PORT with the name of the serial port to use.)
(To exit the serial monitor, type ``Ctrl-]``.)
See the [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html) for full steps to configure and use ESP-IDF to build projects.
## Example Output
### Test uplink bandwidth
* PC: run command: `iperf -u -s -i 3` to start iperf server in UDP mode, and report interval is 3 seconds.
* ESP32: run command: `iperf -u -c PC_IP -i 3 -t 30` to start iperf client in UDP mode, and the test will last 30 seconds.
#### PC output
```bash
------------------------------------------------------------
Server listening on UDP port 5001
Receiving 1470 byte datagrams
UDP buffer size: 208 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.2.160 port 5001 connected with 192.168.2.156 port 49154
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 3] 0.0- 3.0 sec 26.1 MBytes 72.8 Mbits/sec 0.198 ms 1/18585 (0.0054%)
[ 3] 3.0- 6.0 sec 26.3 MBytes 73.7 Mbits/sec 0.192 ms 0/18792 (0%)
[ 3] 6.0- 9.0 sec 26.3 MBytes 73.5 Mbits/sec 0.189 ms 0/18741 (0%)
[ 3] 9.0-12.0 sec 26.2 MBytes 73.3 Mbits/sec 0.191 ms 43/18739 (0.23%)
[ 3] 12.0-15.0 sec 26.3 MBytes 73.5 Mbits/sec 0.194 ms 0/18739 (0%)
[ 3] 15.0-18.0 sec 26.3 MBytes 73.5 Mbits/sec 0.191 ms 0/18741 (0%)
[ 3] 18.0-21.0 sec 26.3 MBytes 73.5 Mbits/sec 0.187 ms 0/18752 (0%)
[ 3] 21.0-24.0 sec 26.3 MBytes 73.4 Mbits/sec 0.192 ms 0/18737 (0%)
[ 3] 24.0-27.0 sec 26.3 MBytes 73.5 Mbits/sec 0.188 ms 0/18739 (0%)
```
#### ESP32 output
```bash
mode=udp-client sip=192.168.2.156:5001, dip=192.168.2.160:5001, interval=3, time=30
Interval Bandwidth
0- 3 sec 72.92 Mbits/sec
3- 6 sec 73.76 Mbits/sec
6- 9 sec 73.56 Mbits/sec
9- 12 sec 73.56 Mbits/sec
12- 15 sec 73.56 Mbits/sec
15- 18 sec 73.56 Mbits/sec
18- 21 sec 73.61 Mbits/sec
21- 24 sec 73.55 Mbits/sec
24- 27 sec 73.56 Mbits/sec
27- 30 sec 73.56 Mbits/sec
0- 30 sec 73.52 Mbits/sec
```
### Test downlink bandwidth
* PC: run command: `iperf -u -c ESP_IP -b 80M -t 30 -i 3` to start iperf client in UDP mode with estimated bandwidth 100M, and report interval is 3 seconds.
* ESP32: run command: `iperf -u -s -t 30 -i 3` to start iperf server in UDP mode, and the test will last 30 seconds.
#### PC output
```bash
------------------------------------------------------------
Client connecting to 192.168.2.156, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 208 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.2.160 port 59581 connected with 192.168.2.156 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 3.0 sec 28.6 MBytes 80.0 Mbits/sec
[ 3] 3.0- 6.0 sec 28.6 MBytes 80.0 Mbits/sec
[ 3] 6.0- 9.0 sec 28.6 MBytes 80.0 Mbits/sec
[ 3] 9.0-12.0 sec 28.6 MBytes 80.0 Mbits/sec
[ 3] 12.0-15.0 sec 28.4 MBytes 79.5 Mbits/sec
[ 3] 15.0-18.0 sec 28.6 MBytes 79.9 Mbits/sec
[ 3] 18.0-21.0 sec 28.6 MBytes 79.9 Mbits/sec
[ 3] 21.0-24.0 sec 28.6 MBytes 79.9 Mbits/sec
[ 3] 24.0-27.0 sec 28.6 MBytes 80.0 Mbits/sec
[ 3] 27.0-30.0 sec 28.5 MBytes 79.7 Mbits/sec
[ 3] 0.0-30.0 sec 286 MBytes 79.9 Mbits/sec
```
#### ESP32 output
```bash
mode=udp-server sip=192.168.2.156:5001, dip=0.0.0.0:5001, interval=3, time=30
Interval Bandwidth
I (2534456) iperf: want recv=16384
0- 3 sec 79.36 Mbits/sec
3- 6 sec 79.56 Mbits/sec
6- 9 sec 79.51 Mbits/sec
9- 12 sec 79.24 Mbits/sec
12- 15 sec 77.33 Mbits/sec
15- 18 sec 79.01 Mbits/sec
18- 21 sec 78.58 Mbits/sec
21- 24 sec 78.24 Mbits/sec
24- 27 sec 79.56 Mbits/sec
27- 30 sec 77.20 Mbits/sec
0- 30 sec 78.76 Mbits/sec
```
## Suggestions of getting higher bandwidth
1. Higher MCU working frequency will get higher bandwidth.
2. Put frequency invoked function into IRAM via macro `IRAM_ATTR` in code.
3. Priority of iperf task may also have effect.
## Troubleshooting
See common troubleshooting for Ethernet examples from [upper level](../README.md#common-troubleshooting).
(For any technical queries, please open an [issue](https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you as soon as possible.)