This article directory

1. Official explanation
2. The -w parameter is used
3. Instructions for specific parameters

1. Official explanation

安装完iperf3 3.13版本后，我们可以通过man iperf3帮助命令看到对-w参数的解释如下：
-w, --window n[KMGT]
set socket buffer size / window size. This value gets sent to the server and used on that side too; on both sides this option sets both the sending and receiving socket buffer sizes. This option can be used to set (indirectly) the maximum TCP window size. Note that on Linux systems, the effective maximum window size is approximately double what is specified by this option (this behavior is not a bug in iperf3 but a “feature” of the Linux kernel, as documented by tcp(7) and socket(7)).

Translation: This parameter is used to set the buffer size or window size of the socket. This setting value will be sent to the server and the configuration will take effect on the server; on the client and server, this parameter will set the sending buffer and receiving buffer at the same time . This parameter can be used to set the maximum value of the TCP window (indirectly). Note that in the Linux system, after configuring this parameter, the effective maximum window size is about twice the set value (this is not a bug of iperf3, this is the system behavior of the linux kernel, refer to TCP(7) and socket(7))

2. The -w parameter is used

Note that the parameter -w can only be entered in the command line of the server, but it will be set to take effect in the receiving and sending buffers of the client and the receiving and sending buffers of the server at the same time.

If you don't want to know the detailed process, you can $conclusion\color{red} directly see the conclusion$ :
If your test goal is to achieve the maximum rate (maximum throughput) of the network, then

$\color{red} If UDP is used, the larger the w parameter, the better$
$\color{red} If you use TCP, unless you know that the throughput is not going up because the receiving window is too small, don't modify the -w parameter lightly, it is recommended to use the -P parameter To better solve this problem; if it is clear that the window is not big enough, then you can use the -w parameter to increase the window$

For details, see: Use iperf3 to perform TCP test on long-fat network (TCP long-fat pipeline), how to configure iperf3

3. Instructions for specific parameters

Through the official description, we already know that the meaning of -w is not the same for TCP and UDP, so the following is divided into two parts: UDP and TCP.

3.1. For UDP, detailed explanation of the use of -w:

UDP sockets have a send buffer size, but there is no UDP send buffer in fact . The actual meaning of the send buffer size is the upper limit of the size of the UDP datagram that can be written to the socket. If the application writes a data packet larger than the upper limit into the socket, the system will return a sending error.

Two factors affect the upper limit of the packet size that UDP can send:

The UDP protocol itself has a 16-bit UDP packet length in the UDP protocol, so the UDP packet length cannot exceed 2^16=65535-20 bytes of IP header=65515 bytes.
The size of the UDP sending buffer of the socket, which limits the length of the maximum UDP message that the application layer can send to the socket, -w can only change this (limited by /proc/sys/net/core/wmem_default, /proc /sys/net/core/wmem_max)

Note that the UDP message should not be sent too large. If it is too large, it is limited by the MTU. The ip will automatically generate fragments. The UDP message will be divided into multiple IP messages. If one ip fragment is lost, the entire UDP message will be discarded.

Let's take UDP one-way test as an example (client send---->server receive)

client:
- Send buffer
  As mentioned above, -w is set, the actual meaning of the size of the send buffer that can be used by the client is the upper limit of the size of the UDP datagram that can be written to the socket, and this value cannot be greater than the maximum value defined by the Linux system , and cannot be smaller than the minimum value defined by the Linux system.
  - When it is less than the minimum value:
    the setting will return success, but it will not take effect, and the minimum value will be used directly.
  - When it is greater than the maximum value:
    because the -w parameter of the client will be synchronized to the server, so when this setting value > the maximum value of the server or this setting value > the maximum value of the client, iperf3 will report an error.
- The receiving buffer (in the one-way test, for the client, no data will be received, so the size of the receiving buffer is meaningless) the receiving
  buffer is meaningful, it can play a buffer role, such as when the CPU is blocked For other high-priority tasks, when iperf3 cannot read data from the socket receiving buffer in a short period of time, if the buffer is too small, packet loss may occur (after the receiving buffer is full, the UDP protocol stack at the receiving end will discard the newly received packet directly), similarly, this value cannot be greater than the maximum value defined by the Linux system, nor can it be less than the minimum value defined by the Linux system.
  - When it is less than the minimum value:
    the setting will return success, but it will not take effect, and the minimum value will be used directly.
  - When it is greater than the maximum value:
    because the -w parameter of the client will be synchronized to the server, so when this setting value > the maximum value of the server or this setting value > the maximum value of the client, iperf3 will report an error.

Server:

Send buffer (in the one-way test, for the server, no data will be sent, so the size of the send buffer is meaningless)
As mentioned above, -w is set, and the client sends the actual size of the send buffer that can be used The meaning is the upper limit of the size of the UDP datagram that can be written to the socket. This value cannot be greater than the maximum value defined by the Linux system, nor can it be less than the minimum value defined by the Linux system.
- When it is less than the minimum value:
the setting will return success, but it will not take effect, and the minimum value will be used directly.
- When it is greater than the maximum value:
Because the -w parameter of the client will be synchronized to the server, when this setting value is greater than the maximum value of the server or this value is greater than the maximum value of the client, iperf3 will report an error.
- Receive buffer
  The receive buffer is meaningful, it can act as a buffer, for example, when the CPU is used by other high-priority tasks, iperf3 cannot read data from the socket receive buffer in a short time, if the buffer is too large If it is small, there may be packet loss (after the receiving buffer is full, the UDP protocol stack at the receiving end will directly discard the newly received packet), if the buffer is large enough, then when such a situation occurs, the buffer The received packets can be cached first and processed after iperf3 returns, so as not to cause packet loss directly . Similarly, this value cannot be greater than the maximum value defined by the Linux system, nor can it be smaller than the minimum value defined by the Linux system.
  - When it is less than the minimum value:
    the setting will return success, but it will not take effect, and the minimum value will be used directly.
  - When it is greater than the maximum value:
    because the -w parameter of the client will be synchronized to the server, so when this setting value > the maximum value of the server or this setting value > the maximum value of the client, iperf3 will report an error.

Conclusion: If UDP is used, the larger the -w parameter, the better without error

3.1.1 How to view the minimum value of UDP sending and receiving buffers defined by the Linux system

How to view the minimum value of the sending and receiving buffer defined by the Linux system:
by opening the -d option, set a very small -w, such as -w 256, you can see the following print

The minimum sending buffer of the client is 4608, and the receiving buffer is 2304


xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -u -b 10M -w 256 -d
send_parameters:
{
    
    
        "udp":  true,
        "omit": 0,
        "time": 10,
        "parallel":     1,
        "window":       256,
        "len":  1448,
        "bandwidth":    10000000,
        "pacing_timer": 1000,
        "client_version":       "3.9"
}
Connecting to host 192.168.3.60, port 5201
SNDBUF is 4608, expecting 256
RCVBUF is 2304, expecting 256
Setting application pacing to 1250000
[  5] local 192.168.3.107 port 39954 connected to 192.168.3.60 port 5201

The minimum sending buffer of the server is 4480, and the receiving buffer is 2240

pi@raspberrypi:~ $ iperf3 -s -A 2 -d
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
get_parameters:
{
    
    
        "udp":  true,
        "omit": 0,
        "time": 10,
        "parallel":     1,
        "window":       256,
        "len":  1448,
        "bandwidth":    10000000,
        "pacing_timer": 1000,
        "client_version":       "3.9"
}
Accepted connection from 192.168.3.107, port 37692
SNDBUF is 4480, expecting 256
RCVBUF is 2240, expecting 256
Setting application pacing to 1250000
[  5] local 192.168.3.60 port 5201 connected to 192.168.3.107 port 39954

3.1.2 How to view the maximum value of UDP sending and receiving buffers defined by the Linux system

client


xxx@xxx-pc:~$ sudo cat /proc/sys/net/core/rmem_max
212992
xxx@xxx-pc:~$ sudo cat /proc/sys/net/core/wmem_max
212992

Server

pi@raspberrypi:~ $ sudo cat /proc/sys/net/core/wmem_max
180224
pi@raspberrypi:~ $ sudo cat /proc/sys/net/core/rmem_max
180224

3.2. For TCP, detailed explanation of the use of -w:

From the article using iperf3 to test the TCP of the long-fat network (TCP long-fat pipeline), how to configure iperf3, we know that the -w parameter can be used to expand the receiving window to solve the problem that the speed of the TCP flow in the TCP long-fat pipeline cannot be increased .

3.2.1. Test environment:

The client uses an 8-core i8 x86 machine with a single-core frequency of 4.0Ghz, while the server uses a Raspberry Pi 4B with a single-core frequency of 1G under the ARM A53 CPU, directly through a gigabit switch Connection, we can see that the bandwidth between the two hosts is 1Gbps, and the RTT is about 0.2ms. Under such a network, we directly use the default parameters for TCP testing. As shown below, it can reach 940Mbps. At this time, the CPU2 of the server has almost reached 100%, which means that due to the limited CPU processing power, 940Mbps is basically the extreme speed of TCP. .

-Client test command:

xxx@xxx-pc:~$ ping 192.168.3.60
PING 192.168.3.60 (192.168.3.60) 56(84) bytes of data.
64 bytes from 192.168.3.60: icmp_seq=1 ttl=64 time=0.150 ms
64 bytes from 192.168.3.60: icmp_seq=2 ttl=64 time=0.192 ms
64 bytes from 192.168.3.60: icmp_seq=3 ttl=64 time=0.206 ms
64 bytes from 192.168.3.60: icmp_seq=4 ttl=64 time=0.219 ms
64 bytes from 192.168.3.60: icmp_seq=5 ttl=64 time=0.195 ms
64 bytes from 192.168.3.60: icmp_seq=6 ttl=64 time=0.214 ms
64 bytes from 192.168.3.60: icmp_seq=7 ttl=64 time=0.202 ms
^C
--- 192.168.3.60 ping statistics ---
7 packets transmitted, 7 received, 0% packet loss, time 6135ms
rtt min/avg/max/mdev = 0.150/0.196/0.219/0.021 ms

xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 58330 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   114 MBytes   955 Mbits/sec    0    390 KBytes
[  5]   1.00-2.00   sec   112 MBytes   942 Mbits/sec    0    390 KBytes
[  5]   2.00-3.00   sec   112 MBytes   942 Mbits/sec    0    390 KBytes
[  5]   3.00-4.00   sec   112 MBytes   942 Mbits/sec    0    390 KBytes
[  5]   4.00-5.00   sec   112 MBytes   942 Mbits/sec    0    390 KBytes
[  5]   5.00-6.00   sec   112 MBytes   942 Mbits/sec    0    390 KBytes
[  5]   6.00-7.00   sec   112 MBytes   942 Mbits/sec    0    390 KBytes
[  5]   7.00-8.00   sec   112 MBytes   942 Mbits/sec    0    390 KBytes
[  5]   8.00-9.00   sec   112 MBytes   936 Mbits/sec    0    390 KBytes
[  5]   9.00-10.00  sec   112 MBytes   942 Mbits/sec    0    390 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  1.10 GBytes   943 Mbits/sec    0             sender
[  5]   0.00-10.02  sec  1.10 GBytes   939 Mbits/sec                  receiver

iperf Done.

Server test command:

pi@raspberrypi:~ $ iperf3 -s -A 2
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.3.107, port 54922
[  5] local 192.168.3.60 port 5201 connected to 192.168.3.107 port 54924
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   110 MBytes   919 Mbits/sec
[  5]   1.00-2.00   sec   112 MBytes   941 Mbits/sec
[  5]   2.00-3.00   sec   112 MBytes   941 Mbits/sec
[  5]   3.00-4.00   sec   112 MBytes   941 Mbits/sec
[  5]   4.00-5.00   sec   112 MBytes   941 Mbits/sec

Server CPU usage:

3.2.2. Simulate the test process of TCP long fat pipeline

We use netem to simulate a long-fat network with a propagation delay of 100ms and 100ms, a total of 200ms, and a bandwidth of 1Gbps.

There is a server input command:

root@raspberrypi:/home/pi# tc qdisc add dev eth0 root netem delay 100ms
root@raspberrypi:/home/pi#

Enter the command on the client:

root@xxx-pc:/home/xxx# tc qdisc add dev enp2s0 root netem delay 100ms
root@xxx-pc:/home/xxx# ping 192.168.3.60
PING 192.168.3.60 (192.168.3.60) 56(84) bytes of data.
64 bytes from 192.168.3.60: icmp_seq=1 ttl=64 time=200 ms
64 bytes from 192.168.3.60: icmp_seq=2 ttl=64 time=200 ms
64 bytes from 192.168.3.60: icmp_seq=3 ttl=64 time=200 ms
^C
--- 192.168.3.60 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 200.252/200.279/200.299/0.019 ms

We can see that the RTT is already 200ms through the ping command.

3.3.3 Test results of TCP in Changfei network

We can see that, using the default parameters, the rate of TCP is very low. After the slow start ramp in the first 3 seconds, the rate finally stabilizes at 105Mbps, which is far from the theoretical value of bandwidth of 1Gbps. At this time, the server with weak processing capacity The occupancy rate of CPU2 is still very low, about 15%, indicating that it is not the CPU processing power that limits the bandwidth, but the TCP long and fat pipeline that limits the rate.

client:


root@xxx-pc:/home/wangsheng# /usr/bin/iperf3 -c 192.168.3.60 -t 10
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 45868 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   740 KBytes  6.06 Mbits/sec    0    113 KBytes
[  5]   1.00-2.00   sec  6.18 MBytes  51.9 Mbits/sec    0   3.51 MBytes
[  5]   2.00-3.00   sec  12.5 MBytes   105 Mbits/sec    0   4.95 MBytes
[  5]   3.00-4.00   sec  12.5 MBytes   105 Mbits/sec    0   4.95 MBytes
[  5]   4.00-5.00   sec  11.2 MBytes  94.4 Mbits/sec    0   4.95 MBytes
[  5]   5.00-6.00   sec  12.5 MBytes   105 Mbits/sec    0   4.95 MBytes
[  5]   6.00-7.00   sec  12.5 MBytes   105 Mbits/sec    0   4.95 MBytes
[  5]   7.00-8.00   sec  12.5 MBytes   105 Mbits/sec    0   4.95 MBytes
[  5]   8.00-9.00   sec  12.5 MBytes   105 Mbits/sec    0   4.95 MBytes
[  5]   9.00-10.00  sec  12.5 MBytes   105 Mbits/sec    0   4.95 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   106 MBytes  88.6 Mbits/sec    0             sender
[  5]   0.00-10.20  sec   105 MBytes  86.1 Mbits/sec                  receiver

iperf Done.

Server:


-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.3.107, port 45854
[  5] local 192.168.3.60 port 5201 connected to 192.168.3.107 port 45868
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  99.0 KBytes   811 Kbits/sec
[  5]   1.00-2.00   sec  3.40 MBytes  28.5 Mbits/sec
[  5]   2.00-3.00   sec  12.4 MBytes   104 Mbits/sec
[  5]   3.00-4.00   sec  12.4 MBytes   104 Mbits/sec
[  5]   4.00-5.00   sec  12.4 MBytes   104 Mbits/sec
[  5]   5.00-6.00   sec  12.4 MBytes   104 Mbits/sec
[  5]   6.00-7.00   sec  12.4 MBytes   104 Mbits/sec
[  5]   7.00-8.00   sec  12.4 MBytes   104 Mbits/sec
[  5]   8.00-9.00   sec  12.4 MBytes   104 Mbits/sec
[  5]   9.00-10.00  sec  12.3 MBytes   103 Mbits/sec
[  5]  10.00-10.20  sec  2.47 MBytes   104 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.20  sec   105 MBytes  86.1 Mbits/sec                  receiver
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

The server CPU usage is about 15%

3.3.3 In the long-fat network: TCP test results after using -w to increase the window

According to the TCP flow control algorithm and congestion control algorithm, in order for TCP to occupy the entire bandwidth (actually bandwidth delay), at least three conditions need to be met
1) The receiving end needs to notify a **bandwidth delay** such a large window, In this way, the sender can send enough data
2) The sender needs to have a sending window with such a large bandwidth * delay, so that the sender can have enough data to send
3) The network cannot be congested, and other traffic cannot be used Occupy the network, otherwise the congestion control algorithm will reduce the throughput

Then use iperf3 to test the long-fat network (TCP long-fat pipeline) according to the long-fat network
and TCP long-fat pipeline. How to configure iperf3 We know that increasing the window size through -w will help to obtain Greater throughput.

Use the following commands to modify the maximum limit of the receiving and sending buffers of the client and server to 64M

echo 33554432 > /proc/sys/net/core/wmem_max
echo 33554432 > /proc/sys/net/core/rmem_max

Below we test separately

-w parameter	TCP throughput rate
1 k	21Kbps
2k	29Kbps
4k	116Kbps
8k	232Kbps
16k	570Kbps
32k	1.2Mbps
64k	2.5Mbps
128k	5.3Mbps
256k	10.7Mbps
512k	20Mbps
1M	42Mbps
2m	84Mbps
4M	168Mbps
8m	336Mbps
16M	603Mbps
24M	776Mbps
26M	840Mbps
28M	900Mbps
29M	923Mbps
30M	944Mbps
31M	944Mbps
32m	944Mbps

At least so far, they are moving in the direction of greater -w and greater throughput, which is also in line with the current author's understanding. We see that when the window reaches 30M, it has reached the limit of 940Mbps, and increasing the size of the window does not help.

The test log is as follows:


xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 1k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 40378 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  2.73 KBytes  22.4 Kbits/sec    0   5.47 KBytes       
[  5]   1.00-2.00   sec  3.28 KBytes  26.9 Kbits/sec    0   5.47 KBytes       
[  5]   2.00-3.00   sec  2.19 KBytes  17.9 Kbits/sec    0   5.47 KBytes       
[  5]   3.00-4.00   sec  3.28 KBytes  26.9 Kbits/sec    0   5.47 KBytes       
[  5]   4.00-5.00   sec  2.19 KBytes  17.9 Kbits/sec    0   5.47 KBytes       
[  5]   5.00-6.00   sec  3.28 KBytes  26.9 Kbits/sec    0   5.47 KBytes       
^C[  5]   6.00-6.49   sec  1.09 KBytes  18.3 Kbits/sec    0   5.47 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-6.49   sec  18.0 KBytes  22.8 Kbits/sec    0             sender
[  5]   0.00-6.49   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 2k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 43396 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  3.54 KBytes  28.9 Kbits/sec    0   7.07 KBytes       
[  5]   1.00-2.00   sec  4.24 KBytes  34.8 Kbits/sec    0   7.07 KBytes       
[  5]   2.00-3.00   sec  2.83 KBytes  23.2 Kbits/sec    0   7.07 KBytes       
[  5]   3.00-4.00   sec  4.24 KBytes  34.8 Kbits/sec    0   7.07 KBytes       
[  5]   4.00-5.00   sec  2.83 KBytes  23.2 Kbits/sec    0   7.07 KBytes       
[  5]   5.00-6.00   sec  4.24 KBytes  34.8 Kbits/sec    0   7.07 KBytes       
^C[  5]   6.00-6.41   sec  1.41 KBytes  28.4 Kbits/sec    0   7.07 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-6.41   sec  23.3 KBytes  29.8 Kbits/sec    0             sender
[  5]   0.00-6.41   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 4k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 41002 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  12.7 KBytes   104 Kbits/sec    0   14.1 KBytes       
[  5]   1.00-2.00   sec  14.1 KBytes   116 Kbits/sec    0   14.1 KBytes       
[  5]   2.00-3.00   sec  14.1 KBytes   116 Kbits/sec    0   14.1 KBytes       
[  5]   3.00-4.00   sec  14.1 KBytes   116 Kbits/sec    0   14.1 KBytes       
[  5]   4.00-5.00   sec  14.1 KBytes   116 Kbits/sec    0   14.1 KBytes       
^C[  5]   5.00-5.38   sec  5.66 KBytes   121 Kbits/sec    0   14.1 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.38   sec  74.9 KBytes   114 Kbits/sec    0             sender
[  5]   0.00-5.38   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 8k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 57816 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  28.3 KBytes   232 Kbits/sec    0   14.1 KBytes       
[  5]   1.00-2.00   sec  28.3 KBytes   232 Kbits/sec    0   14.1 KBytes       
[  5]   2.00-3.00   sec  28.3 KBytes   232 Kbits/sec    0   14.1 KBytes       
[  5]   3.00-4.00   sec  28.3 KBytes   232 Kbits/sec    0   14.1 KBytes       
[  5]   4.00-5.00   sec  28.3 KBytes   232 Kbits/sec    0   14.1 KBytes       
[  5]   5.00-6.00   sec  28.3 KBytes   232 Kbits/sec    0   14.1 KBytes       
[  5]   6.00-7.00   sec  28.3 KBytes   232 Kbits/sec    0   14.1 KBytes       
^C[  5]   7.00-7.43   sec  17.0 KBytes   326 Kbits/sec    0   14.1 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-7.43   sec   215 KBytes   237 Kbits/sec    0             sender
[  5]   0.00-7.43   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 16k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 55020 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  56.6 KBytes   463 Kbits/sec    0   28.3 KBytes       
[  5]   1.00-2.00   sec  84.8 KBytes   695 Kbits/sec    0   28.3 KBytes       
[  5]   2.00-3.00   sec  56.6 KBytes   463 Kbits/sec    0   28.3 KBytes       
[  5]   3.00-4.00   sec  84.8 KBytes   695 Kbits/sec    0   28.3 KBytes       
[  5]   4.00-5.00   sec  56.6 KBytes   463 Kbits/sec    0   28.3 KBytes       
[  5]   5.00-6.00   sec  69.3 KBytes   568 Kbits/sec    0   28.3 KBytes       
[  5]   6.00-7.00   sec  84.8 KBytes   695 Kbits/sec    0   28.3 KBytes       
[  5]   7.00-8.00   sec  56.6 KBytes   463 Kbits/sec    0   28.3 KBytes       
[  5]   8.00-9.00   sec  83.4 KBytes   684 Kbits/sec    0   28.3 KBytes       
[  5]   9.00-10.00  sec  69.3 KBytes   568 Kbits/sec    0   28.3 KBytes       
[  5]  10.00-11.00  sec  56.6 KBytes   463 Kbits/sec    0   28.3 KBytes       
^C[  5]  11.00-11.39  sec  28.3 KBytes   599 Kbits/sec    0   28.3 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-11.39  sec   788 KBytes   567 Kbits/sec    0             sender
[  5]   0.00-11.39  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 32k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 43342 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  94.7 KBytes   776 Kbits/sec    0   62.2 KBytes       
[  5]   1.00-2.00   sec   167 KBytes  1.37 Mbits/sec    0   62.2 KBytes       
[  5]   2.00-3.00   sec   130 KBytes  1.07 Mbits/sec    0   62.2 KBytes       
[  5]   3.00-4.00   sec   147 KBytes  1.20 Mbits/sec    0   62.2 KBytes       
[  5]   4.00-5.00   sec   177 KBytes  1.45 Mbits/sec    0   62.2 KBytes       
[  5]   5.00-6.00   sec   150 KBytes  1.23 Mbits/sec    0   62.2 KBytes       
[  5]   6.00-7.00   sec   119 KBytes   973 Kbits/sec    0   62.2 KBytes       
[  5]   7.00-8.00   sec   171 KBytes  1.40 Mbits/sec    0   62.2 KBytes       
[  5]   8.00-9.00   sec   148 KBytes  1.22 Mbits/sec    0   62.2 KBytes       
[  5]   9.00-10.00  sec   143 KBytes  1.17 Mbits/sec    0   62.2 KBytes       
[  5]  10.00-11.00  sec   146 KBytes  1.19 Mbits/sec    0   62.2 KBytes       
[  5]  11.00-12.00  sec   130 KBytes  1.07 Mbits/sec    0   62.2 KBytes       
^C[  5]  12.00-12.47  sec  77.8 KBytes  1.36 Mbits/sec    0   62.2 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-12.47  sec  1.76 MBytes  1.18 Mbits/sec    0             sender
[  5]   0.00-12.47  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 64k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 34360 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   212 KBytes  1.74 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec   303 KBytes  2.48 Mbits/sec    0    133 KBytes       
[  5]   2.00-3.00   sec   265 KBytes  2.17 Mbits/sec    0    133 KBytes       
[  5]   3.00-4.00   sec   374 KBytes  3.06 Mbits/sec    0    133 KBytes       
[  5]   4.00-5.00   sec   310 KBytes  2.54 Mbits/sec    0    133 KBytes       
[  5]   5.00-6.00   sec   265 KBytes  2.17 Mbits/sec    0    133 KBytes       
[  5]   6.00-7.00   sec   336 KBytes  2.75 Mbits/sec    0    133 KBytes       
[  5]   7.00-8.00   sec   320 KBytes  2.62 Mbits/sec    0    133 KBytes       
[  5]   8.00-9.00   sec   322 KBytes  2.64 Mbits/sec    0    133 KBytes       
[  5]   9.00-10.00  sec   250 KBytes  2.05 Mbits/sec    0    133 KBytes       
^C[  5]  10.00-10.40  sec   166 KBytes  3.37 Mbits/sec    0    133 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.40  sec  3.05 MBytes  2.46 Mbits/sec    0             sender
[  5]   0.00-10.40  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 128k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 59208 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   263 KBytes  2.15 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec   699 KBytes  5.73 Mbits/sec    0    255 KBytes       
[  5]   2.00-3.00   sec   579 KBytes  4.74 Mbits/sec    0    255 KBytes       
[  5]   3.00-4.00   sec   571 KBytes  4.67 Mbits/sec    0    255 KBytes       
[  5]   4.00-5.00   sec   737 KBytes  6.04 Mbits/sec    0    255 KBytes       
[  5]   5.00-6.00   sec   607 KBytes  4.98 Mbits/sec    0    255 KBytes       
[  5]   6.00-7.00   sec   592 KBytes  4.85 Mbits/sec    0    255 KBytes       
[  5]   7.00-8.00   sec   581 KBytes  4.76 Mbits/sec    0    272 KBytes       
[  5]   8.00-9.00   sec   733 KBytes  6.01 Mbits/sec    0    272 KBytes       
[  5]   9.00-10.00  sec   559 KBytes  4.58 Mbits/sec    0    272 KBytes       
[  5]  10.00-11.00  sec   700 KBytes  5.74 Mbits/sec    0    272 KBytes       
^C[  5]  11.00-11.46  sec   296 KBytes  5.28 Mbits/sec    0    272 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-11.46  sec  6.76 MBytes  4.95 Mbits/sec    0             sender
[  5]   0.00-11.46  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 256k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 57688 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   512 KBytes  4.19 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  1.13 MBytes  9.49 Mbits/sec    0    527 KBytes       
[  5]   2.00-3.00   sec  1.26 MBytes  10.6 Mbits/sec    0    527 KBytes       
[  5]   3.00-4.00   sec  1.13 MBytes  9.51 Mbits/sec    0    527 KBytes       
[  5]   4.00-5.00   sec  1.25 MBytes  10.5 Mbits/sec    0    527 KBytes       
[  5]   5.00-6.00   sec  1.18 MBytes  9.88 Mbits/sec    0    527 KBytes       
[  5]   6.00-7.00   sec  1.21 MBytes  10.1 Mbits/sec    0    527 KBytes       
[  5]   7.00-8.00   sec  1.30 MBytes  10.9 Mbits/sec    0    527 KBytes       
[  5]   8.00-9.00   sec  1.33 MBytes  11.1 Mbits/sec    0    527 KBytes       
[  5]   9.00-10.00  sec  1.20 MBytes  10.1 Mbits/sec    0    527 KBytes       
^C[  5]  10.00-10.76  sec  1.01 MBytes  11.1 Mbits/sec    0    527 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.76  sec  12.5 MBytes  9.73 Mbits/sec    0             sender
[  5]   0.00-10.76  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 512k
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 59860 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  1010 KBytes  8.26 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  1.56 MBytes  13.1 Mbits/sec    0   1024 KBytes       
[  5]   2.00-3.00   sec  2.73 MBytes  22.9 Mbits/sec    0   1024 KBytes       
[  5]   3.00-4.00   sec  2.49 MBytes  20.9 Mbits/sec    0   1024 KBytes       
[  5]   4.00-5.00   sec  2.36 MBytes  19.8 Mbits/sec    0   1024 KBytes       
[  5]   5.00-6.00   sec  2.55 MBytes  21.4 Mbits/sec    0   1024 KBytes       
[  5]   6.00-7.00   sec  2.36 MBytes  19.8 Mbits/sec    0   1024 KBytes       
[  5]   7.00-8.00   sec  2.67 MBytes  22.4 Mbits/sec    0   1024 KBytes       
[  5]   8.00-9.00   sec  2.30 MBytes  19.3 Mbits/sec    0   1024 KBytes       
^C[  5]   9.00-9.63   sec  1.99 MBytes  26.6 Mbits/sec    0   1024 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-9.63   sec  22.0 MBytes  19.2 Mbits/sec    0             sender
[  5]   0.00-9.63   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 1m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 35564 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  1.93 MBytes  16.2 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  2.08 MBytes  17.5 Mbits/sec    0   2.01 MBytes       
[  5]   2.00-3.00   sec  5.22 MBytes  43.8 Mbits/sec    0   2.01 MBytes       
[  5]   3.00-4.00   sec  5.34 MBytes  44.8 Mbits/sec    0   2.01 MBytes       
[  5]   4.00-5.00   sec  4.60 MBytes  38.6 Mbits/sec    0   2.01 MBytes       
[  5]   5.00-6.00   sec  5.03 MBytes  42.2 Mbits/sec    0   2.01 MBytes       
[  5]   6.00-7.00   sec  5.16 MBytes  43.3 Mbits/sec    0   2.01 MBytes       
[  5]   7.00-8.00   sec  5.10 MBytes  42.7 Mbits/sec    0   2.01 MBytes       
[  5]   8.00-9.00   sec  4.54 MBytes  38.1 Mbits/sec    0   2.01 MBytes       
[  5]   9.00-10.00  sec  5.28 MBytes  44.3 Mbits/sec    0   2.01 MBytes       
^C[  5]  10.00-10.40  sec  2.17 MBytes  45.2 Mbits/sec    0   2.01 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.40  sec  46.5 MBytes  37.5 Mbits/sec    0             sender
[  5]   0.00-10.40  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 2m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 57468 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  3.75 MBytes  31.4 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  2.50 MBytes  21.0 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  10.0 MBytes  83.9 Mbits/sec    0   4.02 MBytes       
[  5]   3.00-4.00   sec  10.0 MBytes  83.9 Mbits/sec    0   4.02 MBytes       
[  5]   4.00-5.00   sec  10.0 MBytes  83.9 Mbits/sec    0   4.02 MBytes       
[  5]   5.00-6.00   sec  10.0 MBytes  83.9 Mbits/sec    0   4.02 MBytes       
^C[  5]   6.00-6.63   sec  7.12 MBytes  95.6 Mbits/sec    0   4.02 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-6.63   sec  53.4 MBytes  67.6 Mbits/sec    0             sender
[  5]   0.00-6.63   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 4m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 39568 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  6.25 MBytes  52.4 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  2.50 MBytes  21.0 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  20.0 MBytes   168 Mbits/sec    0   5.85 MBytes       
[  5]   3.00-4.00   sec  20.0 MBytes   168 Mbits/sec    0   5.85 MBytes       
[  5]   4.00-5.00   sec  20.0 MBytes   168 Mbits/sec    0   5.85 MBytes       
[  5]   5.00-6.00   sec  20.0 MBytes   168 Mbits/sec    0   5.85 MBytes       
^C[  5]   6.00-6.10   sec  3.75 MBytes   323 Mbits/sec    0   5.85 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-6.10   sec  92.5 MBytes   127 Mbits/sec    0             sender
[  5]   0.00-6.10   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 8m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 50820 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  11.2 MBytes  94.3 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  2.50 MBytes  21.0 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  25.0 MBytes   210 Mbits/sec    0   16.0 MBytes       
[  5]   3.00-4.00   sec  31.2 MBytes   262 Mbits/sec    0   16.0 MBytes       
[  5]   4.00-5.00   sec  33.8 MBytes   283 Mbits/sec    0   16.0 MBytes       
[  5]   5.00-6.00   sec  38.8 MBytes   325 Mbits/sec    0   16.0 MBytes       
[  5]   6.00-7.00   sec  38.8 MBytes   325 Mbits/sec    0   16.0 MBytes       
[  5]   7.00-8.00   sec  40.0 MBytes   336 Mbits/sec    0   16.0 MBytes       
[  5]   8.00-9.00   sec  40.0 MBytes   336 Mbits/sec    0   16.0 MBytes       
[  5]   9.00-10.00  sec  40.0 MBytes   336 Mbits/sec    0   16.0 MBytes       
^C[  5]  10.00-10.37  sec  16.2 MBytes   372 Mbits/sec    0   16.0 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.37  sec   318 MBytes   257 Mbits/sec    0             sender
[  5]   0.00-10.37  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 16m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 54698 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  21.2 MBytes   178 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  47.5 MBytes   399 Mbits/sec    0   33.0 MBytes       
[  5]   3.00-4.00   sec  72.5 MBytes   608 Mbits/sec    0   33.0 MBytes       
[  5]   4.00-5.00   sec  71.2 MBytes   598 Mbits/sec    0   33.0 MBytes       
[  5]   5.00-6.00   sec  71.2 MBytes   598 Mbits/sec    0   33.0 MBytes       
[  5]   6.00-7.00   sec  72.5 MBytes   608 Mbits/sec    0   33.0 MBytes       
[  5]   7.00-8.00   sec  71.2 MBytes   598 Mbits/sec    0   33.0 MBytes       
[  5]   8.00-9.00   sec  71.2 MBytes   598 Mbits/sec    0   33.0 MBytes       
[  5]   9.00-10.00  sec  71.2 MBytes   598 Mbits/sec    0   33.0 MBytes       
^C[  5]  10.00-10.48  sec  35.0 MBytes   610 Mbits/sec    0   33.0 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.48  sec   609 MBytes   487 Mbits/sec    0             sender
[  5]   0.00-10.48  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 24m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 58668 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  31.2 MBytes   262 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  55.0 MBytes   461 Mbits/sec    0   25.8 MBytes       
[  5]   3.00-4.00   sec  92.5 MBytes   776 Mbits/sec    0   25.8 MBytes       
[  5]   4.00-5.00   sec  93.8 MBytes   786 Mbits/sec    0   25.8 MBytes       
[  5]   5.00-6.00   sec  93.8 MBytes   787 Mbits/sec    0   25.8 MBytes       
[  5]   6.00-7.00   sec  90.0 MBytes   755 Mbits/sec    0   25.8 MBytes       
[  5]   7.00-8.00   sec  96.2 MBytes   807 Mbits/sec    0   25.8 MBytes       
[  5]   8.00-9.00   sec  95.0 MBytes   797 Mbits/sec    0   25.8 MBytes       
[  5]   9.00-10.00  sec  92.5 MBytes   776 Mbits/sec    0   25.8 MBytes       
^C[  5]  10.00-10.64  sec  65.0 MBytes   849 Mbits/sec    0   25.8 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.64  sec   809 MBytes   638 Mbits/sec    0             sender
[  5]   0.00-10.64  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 26m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 33020 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  33.8 MBytes   283 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  57.5 MBytes   482 Mbits/sec    0   27.2 MBytes       
[  5]   3.00-4.00   sec  97.5 MBytes   818 Mbits/sec    0   27.3 MBytes       
[  5]   4.00-5.00   sec   101 MBytes   849 Mbits/sec    0   27.3 MBytes       
[  5]   5.00-6.00   sec   101 MBytes   849 Mbits/sec    0   27.3 MBytes       
[  5]   6.00-7.00   sec  97.5 MBytes   818 Mbits/sec    0   27.3 MBytes       
[  5]   7.00-8.00   sec   101 MBytes   849 Mbits/sec    0   27.3 MBytes       
[  5]   8.00-9.00   sec   101 MBytes   849 Mbits/sec    0   27.3 MBytes       
[  5]   9.00-10.00  sec   100 MBytes   839 Mbits/sec    0   27.3 MBytes       
[  5]  10.00-11.00  sec   102 MBytes   860 Mbits/sec    0   27.3 MBytes       
[  5]  11.00-12.00  sec   105 MBytes   881 Mbits/sec    0   27.3 MBytes       
[  5]  12.00-13.00  sec   100 MBytes   839 Mbits/sec    0   27.3 MBytes       
^C[  5]  13.00-13.72  sec  72.5 MBytes   842 Mbits/sec    0   27.3 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-13.72  sec  1.15 GBytes   718 Mbits/sec    0             sender
[  5]   0.00-13.72  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 28m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 39638 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  36.2 MBytes   304 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  57.5 MBytes   482 Mbits/sec    0   27.2 MBytes       
[  5]   3.00-4.00   sec   104 MBytes   870 Mbits/sec    0   29.5 MBytes       
[  5]   4.00-5.00   sec   106 MBytes   891 Mbits/sec    0   29.5 MBytes       
[  5]   5.00-6.00   sec   108 MBytes   902 Mbits/sec    0   29.5 MBytes       
[  5]   6.00-7.00   sec   105 MBytes   881 Mbits/sec    0   29.5 MBytes       
[  5]   7.00-8.00   sec   106 MBytes   891 Mbits/sec    0   29.5 MBytes       
[  5]   8.00-9.00   sec   106 MBytes   891 Mbits/sec    0   29.5 MBytes       
[  5]   9.00-10.00  sec   105 MBytes   881 Mbits/sec    0   29.5 MBytes       
[  5]  10.00-11.00  sec   110 MBytes   923 Mbits/sec    0   29.5 MBytes       
[  5]  11.00-12.00  sec   109 MBytes   912 Mbits/sec    0   29.5 MBytes       
[  5]  12.00-13.00  sec   108 MBytes   902 Mbits/sec    0   29.5 MBytes       
[  5]  13.00-14.00  sec   108 MBytes   902 Mbits/sec    0   29.5 MBytes       
[  5]  14.00-15.00  sec   109 MBytes   912 Mbits/sec    0   29.5 MBytes       
^C[  5]  15.00-15.46  sec  51.2 MBytes   939 Mbits/sec    0   29.5 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-15.46  sec  1.40 GBytes   777 Mbits/sec    0             sender
[  5]   0.00-15.46  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 29m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 49936 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  37.5 MBytes   314 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  57.5 MBytes   482 Mbits/sec    0   27.2 MBytes       
[  5]   3.00-4.00   sec   105 MBytes   881 Mbits/sec    0   30.6 MBytes       
[  5]   4.00-5.00   sec   110 MBytes   923 Mbits/sec    0   30.6 MBytes       
[  5]   5.00-6.00   sec   110 MBytes   923 Mbits/sec    0   30.6 MBytes       
[  5]   6.00-7.00   sec   110 MBytes   923 Mbits/sec    0   30.6 MBytes       
[  5]   7.00-8.00   sec   110 MBytes   923 Mbits/sec    0   30.6 MBytes       
[  5]   8.00-9.00   sec   111 MBytes   933 Mbits/sec    0   30.6 MBytes       
^C[  5]   9.00-9.63   sec  73.8 MBytes   977 Mbits/sec    0   30.6 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-9.63   sec   829 MBytes   722 Mbits/sec    0             sender
[  5]   0.00-9.63   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 30m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 56056 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  38.8 MBytes   325 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  36.2 MBytes   304 Mbits/sec    0   12.2 MBytes       
[  5]   3.00-4.00   sec  53.8 MBytes   451 Mbits/sec    0   14.9 MBytes       
[  5]   4.00-5.00   sec  71.2 MBytes   598 Mbits/sec    0   18.5 MBytes       
[  5]   5.00-6.00   sec  78.8 MBytes   661 Mbits/sec    0   22.4 MBytes       
[  5]   6.00-7.00   sec  88.8 MBytes   744 Mbits/sec    0   26.8 MBytes       
[  5]   7.00-8.00   sec   108 MBytes   902 Mbits/sec    0   31.5 MBytes       
[  5]   8.00-9.00   sec   112 MBytes   944 Mbits/sec    0   31.5 MBytes       
[  5]   9.00-10.00  sec   112 MBytes   944 Mbits/sec    0   31.5 MBytes       
[  5]  10.00-11.00  sec   112 MBytes   944 Mbits/sec    0   31.5 MBytes       
[  5]  11.00-12.00  sec   112 MBytes   944 Mbits/sec    0   31.5 MBytes       
^C[  5]  12.00-12.73  sec  86.2 MBytes   990 Mbits/sec    0   31.5 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-12.73  sec  1015 MBytes   669 Mbits/sec    0             sender
[  5]   0.00-12.73  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 31m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 50572 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  40.0 MBytes   335 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  40.0 MBytes   336 Mbits/sec    0   12.7 MBytes       
[  5]   3.00-4.00   sec  62.5 MBytes   524 Mbits/sec    0   15.8 MBytes       
[  5]   4.00-5.00   sec  77.5 MBytes   650 Mbits/sec    0   19.7 MBytes       
[  5]   5.00-6.00   sec  91.2 MBytes   765 Mbits/sec    0   24.2 MBytes       
[  5]   6.00-7.00   sec   108 MBytes   902 Mbits/sec    0   29.6 MBytes       
[  5]   7.00-8.00   sec   112 MBytes   943 Mbits/sec    0   32.3 MBytes       
[  5]   8.00-9.00   sec   111 MBytes   934 Mbits/sec    0   32.3 MBytes       
[  5]   9.00-10.00  sec   112 MBytes   944 Mbits/sec    0   32.3 MBytes       
[  5]  10.00-11.00  sec   112 MBytes   944 Mbits/sec    0   32.3 MBytes       
[  5]  11.00-12.00  sec   112 MBytes   944 Mbits/sec    0   32.3 MBytes       
[  5]  12.00-13.00  sec   111 MBytes   933 Mbits/sec    0   32.3 MBytes       
^C[  5]  13.00-13.02  sec  1.25 MBytes   446 Mbits/sec    0   32.3 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-13.02  sec  1.07 GBytes   706 Mbits/sec    0             sender
[  5]   0.00-13.02  sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 32m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 33700 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  41.2 MBytes   346 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  45.0 MBytes   378 Mbits/sec    0   47.7 MBytes       
[  5]   3.00-4.00   sec   114 MBytes   954 Mbits/sec    0   66.1 MBytes       
[  5]   4.00-5.00   sec   111 MBytes   933 Mbits/sec    0   66.1 MBytes       
[  5]   5.00-6.00   sec   112 MBytes   944 Mbits/sec    0   66.1 MBytes       
[  5]   6.00-7.00   sec   112 MBytes   944 Mbits/sec    0   66.1 MBytes       
[  5]   7.00-8.00   sec   112 MBytes   944 Mbits/sec    0   66.1 MBytes       
[  5]   8.00-9.00   sec   112 MBytes   944 Mbits/sec    0   66.1 MBytes       
^C[  5]   9.00-9.38   sec  45.0 MBytes   984 Mbits/sec    0   66.1 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-9.38   sec   810 MBytes   724 Mbits/sec    0             sender
[  5]   0.00-9.38   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 64m
Connecting to host 192.168.3.60, port 5201
[  5] local 192.168.3.107 port 56982 connected to 192.168.3.60 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  41.2 MBytes   346 Mbits/sec    0    113 KBytes       
[  5]   1.00-2.00   sec  3.75 MBytes  31.5 Mbits/sec    0   3.54 MBytes       
[  5]   2.00-3.00   sec  58.8 MBytes   493 Mbits/sec    0   27.2 MBytes       
[  5]   3.00-4.00   sec   111 MBytes   933 Mbits/sec    0   32.7 MBytes       
[  5]   4.00-5.00   sec   112 MBytes   944 Mbits/sec    0   33.6 MBytes       
[  5]   5.00-6.00   sec   111 MBytes   933 Mbits/sec    0   33.6 MBytes       
^C[  5]   6.00-6.39   sec  45.0 MBytes   976 Mbits/sec    0   33.6 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-6.39   sec   484 MBytes   635 Mbits/sec    0             sender
[  5]   0.00-6.39   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated
xxx@xxx-pc:~$ /usr/bin/iperf3 -c 192.168.3.60 -t 100 -w 65m
Connecting to host 192.168.3.60, port 5201
iperf3: error - socket buffer size not set correctly

Note: Using a huge window value to improve throughput actually brings the risk of a longer RTT test cycle. A longer RTT measurement cycle means that the TCP protocol stack cannot adapt well to changes in the state of the network.

iPerf3 -w parameter detailed graphic analysis