How to test whether a Asus router is faulty

[Paul Short]

Hi All

I recently sold an Asus RT-AC88U with latest Merlin firmware installed, however it was sent back to me as the buyers claimed it was faulty, apparently he experienced frequent WiFi disconnections. It was returned a few days ago and I have been testing it on my broadband connection and I haven't noticed frequent WiFi disconnection at all. In the last couple of days my household has noticed the odd disconnection from the internet here and there, but only amounting to 4 or 5 at most, and only resulting in webpages loading slower, otherwise the router seems to be functioning as it should.

I was just wondering if there are any tests or methods I can use to test the functionality of the router, particularly it's wireless stability. I have tried continuously pinging 4kb packets from my PC to the router IP address via WiFi for a bit, and the statistics I got were as follows:

Packets: Sent = 2884, Received = 2864, Lost = 20 (0% loss),
Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 105ms, Average = 2ms

My internet connection was in use during this Ping test.

I was just wondering if any of you guys know of any other ways I can check, or whether you can draw any conclusions from the Ping statistics I have added. Any comments would be greatly appreciated.

 

[K-2SO]

There is a good chance wireless disconnections originate from wireless settings. Reset the router first, set it up manually. Disable all PMF, Airtime Fairness, Beamforming, MU-MIMO, non-standard QAM. Use standard non-DFS channels only on 5GHz. 20MHz channel on 2.4GHz. Test again.

 

[ColinTaylor]

WiFi disconnections are a common problem with all devices (routers and clients) as witnessed by the endless posts about them in these forums. That's just the nature of the WiFi beast but it doesn't necessarily mean there's a fault with one device or the other. So if your customer was experiencing a problem with one device (or type of device, i.e. an iPhone) then I'd say "that's life". If on the other hand he was experiencing WiFi disconnections with all his clients then that would be a problem. [Also, user's invariably report "WiFi disconnections" when it's no such thing but actually a different problem.]

There is a good chance wireless disconnections originate from wireless settings. Reset the router first, set it up manually. Disable all PMF, Airtime Fairness, Beamforming, MU-MIMO, non-standard QAM. Use standard non-DFS channels only on 5GHz. 20MHz channel on 2.4GHz. Test again.

The problem with this approach is that whilst it might be possible to tweak the settings so that they are more (or totally) reliable with your home network it is unreasonable to expect a customer to simply use your settings and never change them. The customer would reasonably expect to be able to factory reset the router when it arrives and for it to "just work". Of course whether any WiFi router "just works" with every client is a whole new discussion.

 

[Paul Short]

There is a good chance wireless disconnections originate from wireless settings. Reset the router first, set it up manually. Disable all PMF, Airtime Fairness, Beamforming, MU-MIMO, non-standard QAM. Use standard non-DFS channels only on 5GHz. 20MHz channel on 2.4GHz. Test again.

Many thanks for the reply

I've just looked through the AC88U's GUI just to familiarise myself with all the settings you mentioned. I've found PMF, Airtime Fairness, Beamforming and MU-MIMO settings, plus I know how to disable the option to use DFS channels.

However I don't see a setting for QAM. What I do see that I think relates to QAM is Modulation Scheme, which is currently set to 'Up to MCS 11 (NitroQAM/1024-QAM', with an option to change to 'Up to MCS 9 (802.11ac)', is this what you mean in your comments?

 

[Paul Short]

WiFi disconnections are a common problem with all devices (routers and clients) as witnessed by the endless posts about them in these forums. That's just the nature of the WiFi beast but it doesn't necessarily mean there's a fault with one device or the other. So if your customer was experiencing a problem with one device (or type of device, i.e. an iPhone) then I'd say "that's life". If on the other hand he was experiencing WiFi disconnections with all his clients then that would be a problem. [Also, user's invariably report "WiFi disconnections" when it's no such thing but actually a different problem.]


The problem with this approach is that whilst it might be possible to tweak the settings so that they are more (or totally) reliable with your home network it is unreasonable to expect a customer to simply use your settings and never change them. The customer would reasonably expect to be able to factory reset the router when it arrives and for it to "just work". Of course whether any WiFi router "just works" with every client is a whole new discussion.

Thanks for your comments.

What I can definitely clarify is that the disconnections our household have witnessed since I've been testing this router is that the disconnections that have occurred have on separate devices at different times, not once have numerous devices disconnected at the same time. Incidentally, my partner and I have been using our phones, tablets, laptop and PC through WiFi a lot of the day, and there has been no sign of any disconnections. I am aware that WiFi can be a temperamental beast, but todays usage surely shows the router is performing as well as it should be.

 

[K-2SO]

The problem with this approach is that whilst it might be possible to tweak the settings so that they are more (or totally) reliable with your home network

Correct. It's more like an attempt to eliminate local clients connection issues.

Of course whether any WiFi router "just works" with every client is a whole new discussion.

Exactly.

is this what you mean in your comments?

Yes. Make the WiFi as basic/standard as possible to see if any of your clients have connection issues.

 

[Yesgeek]

Hi All

I recently sold an Asus RT-AC88U with latest Merlin firmware installed, however it was sent back to me as the buyers claimed it was faulty, apparently he experienced frequent WiFi disconnections. It was returned a few days ago and I have been testing it on my broadband connection and I haven't noticed frequent WiFi disconnection at all. In the last couple of days my household has noticed the odd disconnection from the internet here and there, but only amounting to 4 or 5 at most, and only resulting in webpages loading slower, otherwise the router seems to be functioning as it should.

I was just wondering if there are any tests or methods I can use to test the functionality of the router, particularly it's wireless stability. I have tried continuously pinging 4kb packets from my PC to the router IP address via WiFi for a bit, and the statistics I got were as follows:

Packets: Sent = 2884, Received = 2864, Lost = 20 (0% loss),
Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 105ms, Average = 2ms

My internet connection was in use during this Ping test.

I was just wondering if any of you guys know of any other ways I can check, or whether you can draw any conclusions from the Ping statistics I have added. Any comments would be greatly appreciated.

I would look into updating to the latest Merlin firmware. I had a similar issue with my ax88u.

Next time I would revert to Back to Asus OEM firmware And restore to factory settings after before selling it.

 

[K-2SO]

I would look into updating to the latest Merlin firmware.

In your case, I don't know what Merlin is good for in Repeater Mode.

 

[Yesgeek]

In your case, I don't know what Merlin is good for in Repeater Mode.

That’s a good question. I was hoping that maybe he would add WISP mode or wireless double NAT support in the future but I’ve never used the router with stock firmware so I don’t know what the difference is. I’m pretty sure there are some tweaks that help the router run more stable but I don’t know.

I’m sure Asus will be supporting these modes in the future since both OpenWRT and DD-Wrt both support these modes. It seems to be a relatively new feature.

 

[K-2SO]

I’m pretty sure there are some tweaks that help the router run more stable but I don’t know.

You're pretty sure and you don't know in the same time. Are you getting married soon?

 

[Paul Short]

I would look into updating to the latest Merlin firmware. I had a similar issue with my ax88u.

Already has latest Merlin firmware installed. Just wondering if I should test again with OEM firmware, read on another post somewhere else that someone found the OEM firmware was more stable than Merlin.

 

[K-2SO]

read on another post somewhere else that someone found the OEM firmware was more stable than Merlin.

It was me and few others. On a specific model router only though, RT-AC86U. Nothing to do with Merlin's work. The Asus base for this router was flaky for a very long time. Same Merlin firmware versions work totally fine on RT-AC68U. Note the small difference in the model number, 86 vs 68. It's sometimes confusing. I've borrowed an RT-AC68U router to test. Your's should be fine too.

 

[Paul Short]

It was me and few others. On a specific model router only though, RT-AC86U. Nothing to do with Merlin's work. The Asus base for this router was flaky for a very long time. Same Merlin firmware versions work totally fine on RT-AC68U. Note the small difference in the model number, 86 vs 68. It's sometimes confusing. I've borrowed an RT-AC68U router to test. Your's should be fine too.

I will definitely Reset the router and set it up manually using your setting suggestions tomorrow. I'll let you know the results when I've tested it again. Just out of interest, will changing these settings affect the performance of the router at all? I'm hoping it will have a positive effect on the stability of course, but could it slow download and upload rates for example?

 

[K-2SO]

but could it slow download and upload rates for example?

No. Turbo/Nitro-QAM is Broadcomm specific, very few clients support it. Beamforming/MU-MIMO create more compatibility issues than benefits. Your clients must support both. You can leave 802.11ac Beamforming enabled on 5GHz band, if you want. It's part of AC specification. There are settings that don't even apply for specific bands in Asus GUI. Beamforming and MU-MIMO in 2.4GHz band or Tx Bursting on 5GHz band, for example. You'll start to see the marketing side of things reading and understanding what some settings do. I remember Open NAT (port forwarding), Gear Accelerator (Traditional QoS), etc. "gaming" features on my RT-AC86U routers. The best game on this one was called Reboot & Reset.

 

[SwampKracker]

I had an RT-AC68U that was driving me crazy for months. Every time I thought I figured why clients were disconnecting or experiencing low throughput, the problem would always return. The router was defective. It just wasn't completely dead yet.

How did I figure out the problem? I borrowed an RT-AC68P from work and configured it the same as my RT-AC68U. The problems disappeared immediately. Not long after, I reset the RT-AC68U to factory defaults and took it to Best Buy for recycling.

 

[Paul Short]

There is a good chance wireless disconnections originate from wireless settings. Reset the router first, set it up manually. Disable all PMF, Airtime Fairness, Beamforming, MU-MIMO, non-standard QAM. Use standard non-DFS channels only on 5GHz. 20MHz channel on 2.4GHz. Test again.

Ok, tried testing with your configuration settings and these are the results:

Ping statistics for 192.168.1.1:
Packets: Sent = 886, Received = 886, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 112ms, Average = 2ms

Admittedly I only did 15 minute tests, but it has shown that even with changing the settings you mentioned I still get ping spikes. So, I decided to do another 15 minute test using OEM firmware as a comparison, configured how I would normally setup, and here are the results:

Ping statistics for 192.168.1.1:
Packets: Sent = 899, Received = 899, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 117ms, Average = 2ms

Much the same statistics using all three configurations. As I final comparison I setup my ROG GT-AC5300, the router I bought to replace the RT-AC88U, to my normal configuration and performed another 15 minute test. Here are those results:

Ping statistics for 192.168.1.1:
Packets: Sent = 888, Received = 888, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 63ms, Average = 2ms

Still experiencing ping spikes with my new GT-AC5300, albeit not as long trip times.

I can only assume from these results that at least the router is functioning as it should, there doesn't seem to be any signs of a fault, and that my ping spikes must be caused by some other factor, whether it be a connected device, an environmental factor or just the nature of the WiFi signal in my home. I'd be grateful to hear any comments on this please.

 

[K-2SO]

Ping spikes on wireless may be caused by many different factors. Similar results from 2 routers means something external to me. Keep in mind GT-AC5300 is much faster hardware router with newer radios. No surprise it handles your WiFi environment better.

 

[Paul Short]

Ping spikes on wireless may be caused by many different factors. Similar results from 2 routers means something external to me. Keep in mind GT-AC5300 is much faster hardware router with newer radios. No surprise it handles your WiFi environment better.

Cheers for the reply, and for confirming the same thoughts I have that an external factor is causing the ping spikes. The main thing is I seem to have eliminated the fact that the ping spikes are caused by the router itself, and that there doesn't seem to be any fault with the AC88U as the buyer who returned it claims.

Many thanks for all your help, much appreciated.