How to test your router's data transfer speed?

Question

I've an internet connection of 50Mbps, but on speed test on my laptop over WIFI, it shows variable speed, sometimes 20Mbps or sometimes even less than 1Mbps. So I connected WAN cable directly to my laptop, so then it showing the speed of 50Mbps exactly. So I'm pretty sure it is my router's issue. But I want to check what's my router's max speed not the internet. How can I test this?

Answer 1

If you have two available computers, you can measure the TCP speed directly between them, without using file-transfer which is notoriously slow.

The tool to use is iPerf, available for all major operating systems.

For details see the article How to use Iperf to test the speed on TP-Link routers.

The schema of test configuration is:

Use your computer as the server connected via Wifi. Both computers should be on the LAN side of the router. You may connect the computer you are not testing to the router by cable (if faster), to ensure that its performance is not the bottleneck in the test.

The main points are:

• Install iPerf on both computers
• Disable all firewalls
• Set static IP address for PC A
• Set static IP address for WAN port of the Router (your router configuration must support this)

• On PC A start the server:

  Iperf3 -s
  

• on PC B run the command :

  Iperf3  -c  192.168.2.30   (replace IP as required)
  

The result may look like this (on the sender) when the speed is 95 Mbps:

Answer 2

Wi-Fi isn't the best or qualified method to check the router speed, since your connection by Ethernet works gives you the correct speed then the router is fine I guess.

Wi-Fi is great because you don't need cables but still on the other hand the performance varies from many factors:

1. Distance (the bigger the distance the lower signal you get so speed too)
2. channel (an overused channel may drop the speed... with the help of a Wi-Fi Analyzer application you can check and make a decision on changing your channel for better results)
3. obstacles/environment (walls, irons, mirrors or whatever may drop the signal rates and the speed too)
4. another factor is the Wi-Fi dongle.  For example, I have three here, and each of them gives a different performance.