My router is really slow. How can I troubleshoot?

I have two routers at my home.

WAN -(LAN) - Media Link router - (LAN) - Buffalo router - (WiFi IEEE 802.11g) - PC1
                  |- (WiFi IEEE 802.11b/g/n) - PC2

When I compare the speed and stability, PC1 is much better than PC2. I believe my Media Link router has problem. How can I troubleshoot?

The results of Wireless Diagnostics is:

media link  802.11n RSSI:-61    Noise:-92   Band:2.4GHz Width:40MHz
buffalo 802.11b/g   RSSI:-57    Noise:-89   Band:2.4GHz Width:20Mhz

Daisuki Honey

Posted 2014-10-20T05:25:38.597

Reputation: 149

According to the diagram, both are connecting via the Media link, so do you suspect the wifi part of the media link? – Paul – 2014-10-20T05:47:13.243

Yes, both are through Media link. Buffalo should be slower but actually connecting to Media link is slower. So I suspect that Media link's WiFi has problem. – Daisuki Honey – 2014-10-20T16:54:13.680

Check the community wiki answer I put after this question

– agtoever – 2014-10-20T17:59:10.163

Thanks for showing the relevant QA. That answer is great! – Daisuki Honey – 2014-10-21T05:22:21.663

Answers

Check following things on PC2:

Strength of Wifi-Signal, whether the performance get better if the PC is about 3 Meters from the router. (I once have a Laptop that drops Wifi if placed beside the wifi router)
Whether PC2 is using the slow 802.11b.

user3767013

Posted 2014-10-20T05:25:38.597

Reputation: 1 297

Thanks. I have just tired Wireless Diagnostics on my MacBook. I added the result into the original post. Both of my routers are next each other and one of my laptop is there too. Probably I should drop WiFi of that laptop to avoid noise? – Daisuki Honey – 2014-10-20T17:43:47.677

Try disable 40 MHz in media link router. Although 40 MHz meant to give you more throughput, there are more chances that incompatibility results in bad performances. – user3767013 – 2014-10-20T19:53:53.353

According to this article http://lifehacker.com/5931280/optimize-your-wi-fi-network-with-macs-hidden-diagnostic-tool you have a singal noise ratio of 30 dB which is quite good.

– user3767013 – 2014-10-20T20:09:03.063

Thanks for showing great doc. Good to know 30dB is good enough. Let me keep watching. Sometimes the network becomes really slow. I will scan again at that time. Also let me try 20MHz instead of 20MHz/40MHz. – Daisuki Honey – 2014-10-21T05:25:10.520

I bought a router with 5G Hz and has three long antennas. Now I have the following:
RSSI: -61 Noise: -92

Also I haven't seen any wireless issue for the past few weeks.

The point for my situation was: - Use 5GHz channel, which has more vacant channels. - Use a router with good antennas.

Daisuki Honey

Posted 2014-10-20T05:25:38.597

Reputation: 149