Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Table of Content Zone

Table of Contents

...

Web Browser based speed test

For a quick and easy speed test you may use Netflix's HTML based browser test here: fast.com

...

Please :
Note

The accuracy of this speed test diminishes with larger bandwidth circuits

The hardware performance of the computer running this test has a significant impact on results

Any other activity on your network and any devices between your computer and the Internet will impact your speed. 

...

Expand
titleClick here to expand technical details...

Overview

  • iperf is an open source tool. There are clients for Mac, Linux, BSD, etc. There is a port for Windows; however, in our testing we found it to lack certain features and to lag in performance. 
  • iperf operates where one end is the client, the other is the server.


WiscNet Server Details

  • WiscNet runs an iperf version 2 server in Madison, WI. This server has a 10gbps uplink.
  • The server is restricted to WiscNet IP addresses
  • iperf2 and iperf3 are incompatible
  • iperf.wiscnet.net runs a TCP iperf server on the default port 5001
  • iperf.wiscnet.net runs a UDP iperf server on port 5001
  • iperf.ipv6.wiscnet.net runs a v6 TCP iperf server on port 5001
  • iperf.ipv6.wiscnet.net runs a v6 UDP iperf server on port 5001


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).

  • 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.

Some Common iperf Flags

  • Enter iperf -h or man iperf depending on your operating system. Here are some common flags:
FlagDetailsExample
-cClient mode-c
-tTime to run the test in seconds-t 30
-PNumber of parallel connections-P 2
-uUDP (default is TCP)-u
-bBandwidth per thread
-b 250m
-iInterval between bandwidth reports in seconds-i 1
-L
Listen on port-L 5001
-r
bidirectional test (individually)-r
-d
bidirectional test (simultaneously)-d
-VUse ipv6 (this is required even when specifying an IPv6 address)-V



Please note:
Note

The hardware performance of the client running this test has a significant impact on results

WiscNet has noticed that the iperf clients for Linux, Unix, and macOS perform better than the ports for Windows

These commands are for iperf 2, not iperf 3

...