How to troubleshoot lag spikes/packet loss to router on WiFi?

ABadUserName

Distinguished
Nov 2, 2010
19
0
18,510
This is what my internet looks like sometimes:

03.05.2018-18.27.png


03.05.2018-19.55.png


This one is me sitting in the same room as the router literally 6 feet away:
03.05.2018-18.56.png


And here's the picture from my housemate's computer in his room over the same time span
2018-03-05_1857.png



This lag happens on both 2.4 and 5G, and it happens to both me and my housemates. Sometimes I lag but I ask my housemate who is right in the room next to me and he isn't lagging at all (even during huge packet loss for me like the first picture). And sometimes it affects us all at once.

I have tried:
-Restarted the router and modem many times
-Updating router firmware and my WiFi drivers
-Changing the frequency channel on the router
-The router is only 6 months old

Router: Archer C7 | AC1750
Laptop: Dell XPS 9560

How can I determine the cause / fix this?
 
Solution
Any chance that the lags are caused by too much wireless traffic?

E.g., one device (laptop in question perhaps) trying to do some software update or otherwise "phone home".

Tries and gives up.

Then later tries again and the lags re-occur.

Could try wired connections for the PC and/or Xbox either directly or via powerline devices as suggested by @bill001g.

Maybe direct wired for testing and then evolve to powerline adapters so there are no Ethernet cables strung all about.


ABadUserName

Distinguished
Nov 2, 2010
19
0
18,510


I use a laptop (Dell XPS 9560) and the network adapter is the Intel Dual Band Wireless-AC 8260, it is about 4 months old. My housemates are also having the same problem so I don't think it would be the problem.



The only other devices on the floor are phones, laptops and Xbox One. The other wireless networks are the basement tenant and adjacent houses.

I tried sitting in the living room with my laptop sitting 5 feet in front of the router with no other devices in the room and still saw the lag spikes shown in my picture.
 

Ralston18

Titan
Moderator
How many devices total?

Check all wired network connections. Look for any loose plugs etc. Even though you are using wireless there are wires involved. A loose connection may disrupt everything and everyone (i.e., "housemates").

Run tracert and pathping via the command prompt.

The goal is to determine if the lags are inside or outside of your network.
 

ABadUserName

Distinguished
Nov 2, 2010
19
0
18,510


There are no devices plugged in to the router, we're only using WiFi.

Right now there are 6 on 2.4G (1 laptop, 1 PC, 3 phones, Xbox) and 2 on 5G (2 laptops). This is among only 3 people though so they aren't all actively using much internet, just connected to the WiFi.

The issue has stopped for now (it comes and goes), so I'll come back with the tracert and pathping when it's bad again.
 
I really wish they did not lock the chipset firmware up so much. It would be nice if the wifi chips reported for example how many errors and what types they were seeing with the transmissions.

Wifi, unlike almost any other network connectivity, attempt to correct data errors. If the data is detected as damaged it will re transmit the data until it gets a clean copy or some time expires. This is what causes these large delays between your pc and the router.

It could be software in the router or in the pc but that is not very likely. The most common cause is a interfering signal. Now you might get lucky and find it is some device in your house, like a cordless phone or baby monitor. Most times it is signals coming from outside your house from say a neighbors router. It can even come from a newer car driving past your house that has one of those built in hotspot systems.

Most times your only option to fix interference is to try to avoid it. There are few options though. You can try different radio channels but in most places you will find devices on every possible channel. You can try forcing the router to use only 20mhz channels. This will cut your top speed but it increases your chance of finding less used radio channels. The newest tri-band routers run 2 80mhz wide radios on 5g by default. The is only 180mhz total so you pretty much will guarantee overlap with any neighbors.
 

ABadUserName

Distinguished
Nov 2, 2010
19
0
18,510


Okay I ran tracert and pathping during some lag spikes

03.07.2018-02.30.png


03.07.2018-02.32.png


 
This shows why tracert can not really be believed it does not send enough data so you get inconsistent results. It says the connection to your router is fine and it is your ISP. This likely is not valid data since other people in the house are not affected.

Because you are running pathping to your router and seeing this problem it means it has to be the wifi...you could try it again on ethernet to confirm. You could I suppose run pathping to a common address like 8.8.8.8 but pathping would still likely show issues to your router.

Try using the laptop next to the router to see if it is the location or something with the laptop itself causing the problem.

Unless for example the card in your laptop was defective or you have a driver problem there is not a lot you can do about the wifi signal itself....or more likely interference from a outside source.

Although you can chase this problem you may not find a real solution. If you get good results on ethernet I would consider using powerline devices rather than wifi.
 

Ralston18

Titan
Moderator
Any chance that the lags are caused by too much wireless traffic?

E.g., one device (laptop in question perhaps) trying to do some software update or otherwise "phone home".

Tries and gives up.

Then later tries again and the lags re-occur.

Could try wired connections for the PC and/or Xbox either directly or via powerline devices as suggested by @bill001g.

Maybe direct wired for testing and then evolve to powerline adapters so there are no Ethernet cables strung all about.


 
Solution

ABadUserName

Distinguished
Nov 2, 2010
19
0
18,510


Ok I will look into powerline adapters, thanks. I think we already ruled out congestion because in the past we tried turning off all devices and having only one laptop connected, and still had the issue.