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Elastic Compute Service

Network performance test

Using iPerf3 to test network performance

This topic describes how to use iPerf3 to test ECS instance network performance.

iPerf3 overview

iPerf3 is a tool for testing the maximum available bandwidth on IP networks. It allows you to adjust parameters related to timing, buffers, and protocols (TCP, UDP, SCTP, IPv4, and IPv6). It offers detailed test reports on network bandwidth, delay jitter, and packet loss rate.

Procedure

tip

Test results provided in this topic are for reference only and do not represent the actual optimal performance of an ECS instance.

Step 1: Prepare the environment

Refer to the practice of purchasing an ECS instance to create the DUT and Testers. The test environment provided in this topic is shown in the table below:

ECS instance	ECS instance information	Quantity	IP address	Description
DUT	Image: Debian 10 64 bit Instance type: ecs.ebmg2i.32xlarge	1	172.0.0.1	The instance under network PPS stress testing. It can serve as both the Client and the Server in an iperf3 test.
Tester	Image: Debian 10 64 bit Instance type: ecs.ebmg2i.32xlarge	4	172.0.0.2 ~ 172.0.0.5	The instances for creating control connections with the DUT to transmit test details and results. They can serve as both the Client and the Server in an iperf3 test.

tip

All ECS instances need to be associated with the same security group.

Step 2: Install iperf3

On the DUT and the Testers, execute the following commands to install iperf3.

apt update
apt install -y iperf3

Step 3: Test network performance

Inbound direction test

On the DUT, start 128 iperf3 server processes.

Distribute 128 iperf3 servers evenly to four Testers. On each Tester, start 32 iperf3 server processes.

On the DUT (172.0.0.1), create the script server.sh, and then grant execution permission.

Execute the vim server.sh command to create the server.sh file.

Press i to enter the edit mode.

In the server.sh file, enter the following content.

#! /bin/bash

proc_num=$1
port_begin=12000
ls
for ((i=0; i<proc_num; i++))
do
port=$((port_begin + i))
cpu=$((i%$1 + 1))

iperf3 -s -i 1 -p $port -A $(( $cpu % $1 )) -D > /dev/null &
done

Press Esc to exit the edit mode, input :wq and press Enter.

Execute the chmod +x server.sh command to grant execution permission to the server.sh file.

On the DUT (172.0.0.1), run ./ server.sh 128 to start 128 iperf3 server processes.

On each Tester, create the script client.sh, and then grant execution permission.

Execute the vim client.sh command to create the client.sh file.

Press i to enter the edit mode.

In the client.sh file, enter the following content.

#! /bin/bash

dst_ip=$1
proc_num=$2
port_begin=12000

for ((i=0; i<proc_num; i++))
do
port=$((port_begin + i))
iperf3 -c $dst_ip -u -l 16 -b 10000M -i 1 -t 3600 -p $port -A $(( $i % $2)) -P 1 > /dev/null 2>&1 &
done

tip

Specify the values of parameter port_begin of the four Testers incrementally. For example:

172.0.0.2: 12000

172.0.0.3: 12032

172.0.0.4: 12064

172.0.0.5: 12096

Press Esc to exit the edit mode, input :wq and press Enter.

Execute the chmod +x client.sh command to grant execute permission to the client.sh file.

On each Tester, execute the ./client.sh 172.0.0.1 32 command to start 32 iperf3 client processes.

On the DUT, execute the sar -n DEV 1 command to view the test results.

Outbound direction test

Distribute 128 ports evenly to four Testers. On each Tester, start 32 iperf client processes.

The DUT (172.0.0.1) starts 32 iperf3 client processes to each Tester (172.0.0.2 to 172.0.0.5) to generate traffic, resulting in 128 iperf3 client processes in total.

On each Tester, create the script server.sh, and then grant execution permission.

Execute the vim server.sh command to create the server.sh file.

Press i to enter the edit mode.

In the server.sh file, enter the following content.

#! /bin/bash

proc_num=$1
port_begin=12000

for ((i=0; i<proc_num; i++))
do
port=$((port_begin + i))
cpu=$((i%$1 + 1))

iperf3 -s -i 1 -p $port -A $(( $cpu % $1 )) -D > /dev/null &
done

tip

Specify the values of parameter port_begin of the four Testers incrementally. For example:

172.0.0.2: 12000

172.0.0.3: 12032

172.0.0.4: 12064

172.0.0.5: 12096

Press Esc to exit the edit mode, input :wq and press Enter.

Execute the chmod +x server.sh command to grant execution permission to the server.sh file.

Execute ./server.sh 32 on the Testers to start 32 iperf3 server processes.

On the DUT (172.0.0.1), create the script client.sh, and then grant execution permission.

Execute the vim client.sh command to create the client.sh file.

Press i to enter the edit mode.

In the client.sh file, enter the following content.

#! /bin/bash

dst_ip=$1
port_begin=$2
cpu_start=$3
proc_num=$4

for ((i=0; i<proc_num; i++))
do
port=$((port_begin + i))
cpu=$((cpu_start + i))
iperf3 -c $dst_ip -u -l 16 -b 10000M -i 1 -t 180 -p $port -A $(( $cpu % $4)) -P 1 > /dev/null 2>&1 &
done

Press Esc to exit the edit mode, input :wq and press Enter.

Execute the chmod +x client.sh command to grant execute permission to the client.sh file.

On the DUT (172.0.0.1), execute the following commands to run the client.sh script file.

./client.sh 172.0.0.2 12000 0 128
./client.sh 172.0.0.3 12032 32 128
./client.sh 172.0.0.4 12064 64 128
./client.sh 172.0.0.5 12096 96 128

Execute the sar -n DEV 1 command on each Tester and view the test results.

Then, sum up the results obtained in the four Testers to obtain the test result for DUT. For example: 3790019 + 3183582 + 3500913 + 3564047, which adds up to about 14 Mpps.

Last updated: 2026.10.19 19:42:20