Intermittent high ping (on both Asus RT-N66U and Asus RT-AC68U)

[codemonkey]

Hi all, first post here so sorry if this is blindingly obvious to you all or covered in an FAQ etc somewhere!

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I had this problem with my RT-N66. First of all I bought a new wireless card for my Dell XPS 13 9343, as the stock one is said to be a bit, well, rubbish.

Sadly that made no difference, so I decided to buy an AC68U to replace the N66U that I've had for years.

Still no difference.

If I leave a cmd window open on my laptop with ping 8.8.8.8 -t running I can see that when things are good, I get 20ms. When they occasionally go bad, it spikes all over the place, up to 3000ms.

Here's the weird thing; if I open up the Asus router and go to system tools and do a ping of 8.8.8.8 in there, suddenly the ping on my laptop drops back down to 20ms. The ping on the router is ALWAYS 20ms.

Rebooting the router appears to make no difference to my problems. Nor does rebooting my laptop.

The natural assumption is that I have some interference causing problems in the house, but I've no idea what it would be. We live in a detached house and there's no other wifi around to worry about. I sit maybe 4-5m from the router.

I choose to use the 2.4GHz channel for better range (large house), and have actually disabled the 5GHz one for simplicity (got bored of visitors asking which wifi they should connect to). What other items in my house might be trying to use the 2.4GHz channel? We have a wireless thermostat (nothing fancy, a Sunvic TLX-1010). I've tried to find out what frequency that uses but can't find any information related to it. Could it be that simple?

 

[Klueless]

Like you say, 2.4 GHz interference could be a problem. Typical culprits are baby monitors and old 2.4 GHz cordless phones. Your thermostat claims it's 868 MHz.

You didn't mention whether you had the same problems over wired Ethernet or over 5 GHz? You also didn't mention whether you were using ping to troubleshoot performance problems or if you used ping just because you were curious?

Here's the weird thing; if I open up the Asus router and go to system tools and do a ping of 8.8.8.8 in there, suddenly the ping on my laptop drops back down to 20ms. The ping on the router is ALWAYS 20ms.

Now that is a kicker! I had some ideas until I read that. What in the Blue Suzy!

Some thoughts:

• I think you've done a great job with your empirical analysis.
• Verify that you do or don't have the same problem over Ethernet and 5 GHz.
• Load a WiFi analyzer onto your PC, laptop or smart phone and reverify you don't have any other WiFi devices/contention around your detached house. (You left me assuming you did this by visual observation.)
• Instead of "ping" you might consider loading "Ping Plotter" on your laptop? It does a "tracert" (Trace Route), kind of like a ping to every device between you and 8.8.8.8 and gives you a graph/chart of the results (on the off-chance it's some device out in the Internet). It could also verify your suspicion that high ping times are in-house. In the long run it's easier; run it all day and scroll through the chart later. (As an alternative you could try one of your all day pings to your router ... presumably 192.168.1.1 instead of 8.8.8.8 ... If you experience the same phenomena it strengthens your case that the problem is in-house.)
• Just as an aside, if you're having no performance problems, just ping problems, you should realize that "ping" is an extremely low priority protocol. If something is busy it'll only process pings when it gets around it (but that doesn't explain why pinging from your router would fix it).

I had a similar problem once. Ping Plotter showed it to be one of my ISP's routers. But my problem never cleared up if I pinged from my router. That's just crazy.

got bored of visitors asking which wifi they should connect to

Set things the way you like then set up an SSID for visitors at 2.4 and simply call it "Guest".