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Considerations

1. For

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• The accuracy of this speed test diminishes with larger bandwidth circuits
• The hardware performance of the client running this test has a significant impact on results

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WiscNet hosted Iperf

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• The hardware performance of the client running this test has a significant impacts results
• WiscNet has noticed that the Iperf clients for Linux, Unix, and macOS perform better than the ports for Windows

1. best results test with a wired (copper/fiber) connection.
2. The performance of the computer running this test may have a significant impact on the test results.
3. Other activity on your network may impact your test results significantly.
   
   1. For better results, bypass your network during and outage window and test directly from the Network Access handoff.
   2. If this is not an option, we recommend connecting your test computer to your network as close as possible to the Network Access handoff.
      
4. graphs.wiscnet.net uses 5 minute polling and averages, so short speed tests that will fall within a 5 minute polling cycle won't be reflected as maximums on graphs.wiscnet.net.
5. iperf3 performance is better than web browser based tests.

Web Browser Speed Tests

WiscNet iperf Speed Tests

Iperf Info

• iperf is a network testing tool used to help measure network throughput, iperf is developed by ESnet / Lawrence Berkeley National Laboratory. For more information please visit:
  • http://software.es.net/iperf/
  • https://github.com/esnet/iperf

• WiscNet hosts both iperf2 and iperf3
  • Use iperf3 per recommendations below
  • Both are on the server iperf.wiscnet.net

• iperf.wiscnet.net is only available to WiscNet members
  • WiscNet also hosts a perfsonar server, which is available publicly - https://www.perfsonar.net/

iperf3 Installation

There are many publicly available guides online. Here are some common examples:

Windows with Windows Subsystem for Linux (Debian/Ubuntu):

sudo apt install iperf3

macOS with Homebrew:

brew install iperf3

Linux - Redhat:

sudo dnf install iperf3

Linux - Debian:

sudo apt install iperf3

iperf3 Test Examples

We recommend using iperf3 TCP tests with four parallel threads when possible for up to 10Gbps tests. UDP tests (not documented here) may cause a service interruption if not used carefully.

iperf3 Download Test

iperf3 testing download speeds from the member's perspective, 4 threads in parallel, for 900 seconds/15 minutes, using TCP. The [SUM] row results in Mbits/sec or Gbits/sec.

iperf3

Some common Iperf flags

Enter iperf -h or man iperf depending on your operating system. Here are some common flags:

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-b 250m

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-L

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-r

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-d

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TCP vs UDP testing

Iperf uses TCP by default. TCP has built in congestion avoidance. If TCP detects any packet loss, it assumes that the link capacity has been reached, and it slows down. This works very well, unless there is packet loss caused by something other than congestion. If there is packet loss due to errors, TCP will back off even if there is plenty of capacity. iperf allows TCP to send as fast as it can, which generally works to fill a clean, low latency link with packets. If a path is not clean/error free or has high latency, TCP will have a difficult time filling it. For testing higher capacity links and for links with higher latency, you will want to adjust the window size (-w option). See the KB article on TCP performance for more background.

By using the -u option, you have told iperf to use UDP packets, rather than TCP. UDP has no built in congestion avoidance, and iperf doesn't implement it either. When doing a UDP test, iperf requires that the bandwidth of the test be specified. If it isn't, it defaults to 1Mb/s. You can use the -b option to specify bandwidth to test. iperf will then send packets at the request rate for the requested period of time. The other end measures how many packets are received vs how many were sent and reports its results.

Examples

Unidirectional UDP 1Gbps circuit test

Command

iperf -c iperf.wiscnet.net -t 10 -P 4 -u -b 250mt 900 -i1R

Results

When runing multiple threads you must look at the SUM lines for total throughput. Output below shows successfully getting 953Mbits/sec through

 -c iperf.wiscnet.net

 -P 4 -

t 900 -

iperf3

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R

<output shortened/omitted>
- - - - - - - - - - - - - - - - - - - - - - - - -
[ 7] 8.00-9.00 sec 31.6 MBytes 265 Mbits/sec 
[ 9] 8.00-9.00 sec 20.2 MBytes 170 Mbits/sec 
[ 11] 8.00-9.00 sec 33.4 MBytes 280 Mbits/sec 
[ 13] 8.00-9.00 sec 25.5 MBytes 214 Mbits/sec 
[SUM] 8.00-9.00 sec 111 MBytes 929 Mbits/sec 

<repeats until the test is completed>
<output shortened/omitted>

iperf3 Upload Test

iperf3 testing download speeds from the member's perspective, 4 threads in parallel, for 900 seconds/15 minutes, using TCP. The [SUM] row results in Mbits/sec or Gbits/sec. "-R" for reverse added to this test.

iperf3

Command

iperf -c iperf.wiscnet.net -t 10 -P 4 -u -b 250m -i1 -r

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Apple macOS

• Download and extract Bandwidth Testing to any folder
• Open a terminal
• cd to your extracted iperf folder

macOS - Install

iMac:~ $ cd Downloads/iperf-2.0.5-macos-x86_64

iMac:iperf-2.0.5-macos-x86_64 $ ls -lh
total 176
-rw-r--r--  1   staff   693B Feb 20  2011 README
drwxr-xr-x@ 8   staff   272B Feb 20  2011 doc
-rwxr-xr-x@ 1   staff    78K Feb 20  2011 iperf
-rw-r--r--@ 1   staff   3.7K Feb 20  2011 iperf.1

macOS - Example 

iMac:iperf-2.0.5-macos-x86_64 $ ./iperf -c iperf.wiscnet.net
------------------------------------------------------------
Client connecting to iperf.wiscnet.net, TCP port 5001
TCP window size:  128 KByte (default)
------------------------------------------------------------
[  5] local 10.0.10.100 port 51961 connected with 205.213.14.56 port 5001
[ ID] Interval       Transfer     Bandwidth
[  5]  0.0-10.0 sec   184 MBytes   154 Mbits/sec
iMac:iperf-2.0.5-macos-x86_64 $

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t 900

iperf3 -c iperf.wiscnet.net -P 4 -t 900

<output shortened/omitted>
- - - - - - - - - - - - - - - - - - - - - - - - -
[ 7] 8.00-9.01 sec 22.4 MBytes 187 Mbits/sec 
[ 9] 8.00-9.01 sec 24.9 MBytes 208 Mbits/sec 
[ 11] 8.00-9.01 sec 22.4 MBytes 187 Mbits/sec 
[ 13] 8.00-9.01 sec 41.4 MBytes 346 Mbits/sec 
[SUM] 8.00-9.01 sec 111 MBytes 928 Mbits/sec 

<repeats until the test is completed>
<output shortened/omitted>

Specifying IPv4 or IPV6

• iperf.wiscnet.net listens on v4 and v6. If you wish to test only v4 or only v6, please use the hostnames below (same server)
  • iperf-ipv4.wiscnet.net
  • iperf-ipv6.wiscnet.net

• Many Lunix and Unix distros will have iperf in official repositories. Make sure to install iperf2 (iperf), not iperf3

Ubuntu - Install

$ apt-cache search iperf | grep -i iperf
iperf - Internet Protocol bandwidth measuring tool
iperf3 - Internet Protocol bandwidth measuring tool
$ sudo apt-get install iperf

Ubuntu - Example

user@Latitude-E7440:~$ iperf -c iperf.wiscnet.net -t 10 -P 4
------------------------------------------------------------
Client connecting to iperf.wiscnet.net, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[  4] local 10.0.10.168 port 37014 connected with 205.213.14.56 port 5001
[  3] local 10.0.10.168 port 37010 connected with 205.213.14.56 port 5001
[  6] local 10.0.10.168 port 37016 connected with 205.213.14.56 port 5001
[  5] local 10.0.10.168 port 37012 connected with 205.213.14.56 port 5001
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec   266 MBytes   222 Mbits/sec
[  5]  0.0-10.0 sec   264 MBytes   221 Mbits/sec
[  3]  0.0-10.0 sec   278 MBytes   233 Mbits/sec
[  6]  0.0-10.0 sec   310 MBytes   259 Mbits/sec
[SUM]  0.0-10.0 sec  1.09 GBytes   934 Mbits/sec
user@Latitude-E7440:~$ 

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Windows - Install

• Download and extract iperf2: Bandwidth Testing
• Right-click the downloaded iperf-2.0.10-win32.zip file and extract the contents of the .zip to any folder (seen here under \Users\Administrator)

Image Removed

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cd \Users\Administrator\iperf-2.0.10-win\
dir 

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Windows - Example

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