Question Interference from somewhere causes Ping Spikes and Packet Loss ?

Jul 19, 2022
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Hello everyone,

I started to play Valorant and realized that something is wrong with my home network since I suffer from severe ping spikes and packet loss.
My setup:

Zyxel VMG1312-B30A as modem in bridge mode with a router running OpenWRT behind it.

My gaming PC is connected via LAN. I changed every cable, tried to reset settings on every device and ran tests with different settings (especially QoS/SQM). Nothing seemed to be able to fix this. Then I tried to connect my gaming PC directly to the Zyxel Modem/Router and voilà - the issues are gone. I thought that I could just use the router for all other (Wifi) devices in my home and have the PC hooked up to the modem. But - and this is why I'm posting here - I realized that the network problems are present as soon as the router runs, so it looks like there's some kind of intereference going on ?

Modem and router are plugged into two different sockets and the issues persist even when I deactivate wifi and remove every LAN cable from the router so that it draws no bandwith. Do you have any idea what might be happening here? Maybe some crappy domestic wiring?
 
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Cyberat_88

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Apr 9, 2011
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I presume your modem is also a router, given the bridge. Is it or not ?
A wi-fi router is also a LAN so what were you connected to when problems started ?
Did you setup router behind router in "modem" ? Did you plug the router WAN into the modem LAN ?
 

gggplaya

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You need to be more specific about what exact router you have with OpenWRT. Typically when using 3rd party firmware, you lose hardware NAT and the router becomes very cpu limited If it's a cheaper router with a slower processor, it may not be able to run NAT very fast, or software libraries in OpenWRT can slow down the network. That's why I built my own x86 router using old computer parts when running openWRT. I can run whatever I want and still have plenty of cpu power left over.
 
Jul 19, 2022
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thank you for your responses! The modem can work as a router but is in bridge mode right now. The problems occured right when we moved in and there's no difference between

SETUP A: Modem in bridge mode > Gaming PC via LAN
SETUP B: Modem as router > Gaming PC via LAN
SETUP C: Modem in bridge mode > router via LAN > Gaming PC via LAN.

Whenever the router and the modem are running at the same time, I experience the problems I described above.
I'm using a TP Link Archer C7 V5 with SQM being the only additional package that I installed. CPU load never exceeds 70% and usually sits around 20-30%.

But again: the problems that I described also occure when the PC is not connected to the router but directly to the modem. So I really think that there is some kind of electronical issue here.

Edit: The issues starts a couple of seconds after I plug in the router - even when there's nothing connected to it and both wifi interfaces (5 and 2,4 ghz) are turned off - and disappear right after I pull the router's plug again
 

gggplaya

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For future reference, that router uses a single core 750mhz Qualcomm Atheros QCA9563 processor. It's not very fast, so running SQM with FQ_Codel or Cake will be severely limited due to the slower cpu, maybe 100-150mbps max WAN speed is my guess. What's your internet plan max speed?

I'm not a fan of Zyxzel products. But as long as you're confident you have it properly in bridge mode, then it shouldn't be an issue.

Does it lag in other games?

Do you have a friend that can bring a laptop or other PC over to try out?
 
Jul 19, 2022
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Unfortunately, the bandwith is restricted to 40 down/10 up - still waiting for fiber... - but even with SQM (cake), the cpu load was not above 20% during my tests (wifi off, pc as only device that was connected).
I experience Packet Loss in every game I tested (e.g. CS 1.6, Halo Infinite, Fall Guys) and I can easily reproduce this with different computers (tried 2 laptops that work perfectly fine at a friend's place). We had the same setup in our former apartment which is why I think that it has something to do with the wiring. I just tried to run an extension cord in order to plug the router into a different socket in another room and had no issues whatsoever. I just don't understand what kind of problem there might be and if there's a way an electrian could fix this. I'm trying to understand what's going on so that I can let my landlord know.
 

gggplaya

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You have DSL, which means it runs from your copper phone lines. My guess is that the phone line in that house might not be twisted or have enough twists to sustain 40mbps properly.

I would find where your phone line enters the apartment from outside. Then try to connect your modem to that location and eliminate any long runs of phone cord. You may need to buy an RJ-11 phone jack for that location and wire it in.

When playing a game, try also continuously pinging www.google.com or similar server in command prompt. See if there are latency spikes. Helps to have a second screen:

Use command: ping -t www.google.com
 
Jul 19, 2022
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But again: These problems are gone whenever I unplug the router. So I can easily play with my pc connected directly to the modem. the issues are only there whenever I plug my router in even when it is not connected to anything and set back to factory (TP-Link firmware) settings
 
Jul 19, 2022
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the router is not connected to anything so I don't think that I can be an IP conflict if the only connection exists between the gaming PC and the modem. I also just tested it with an older FritzBox Modem/Router and got the exact same result - regular ping spikes and packet loss. you can see the ping spike every 2-3s when the router is plugged into the socket but not connected to anything (wifi turned off as well). these problems are completely gone once I unplug the router or connect it to a different socket. I could just move the router to a different room but that would mean that I would need to use an additonal AP in order to have a strong wifi signal in the whole apartment. That's why I'm trying to understand what kind of electrical issue this could be so that I can tell my landlord or an electrican something they can actually act on (and not: "my ping spikes when I'm gaming").

Edit: I just realized that even a lamp plugged into the 'faulty' socket leads to the same problem
 

gggplaya

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Now I'm really confused because your information is conflicting.

Zxyzel Modem --> PC you have no issues, everything is fine as expected. This rules out a DSL wiring issue and modem issue.

Zyxel Modem -->TPlink or Frtizbox Router -->PC you have issues. But like I said, what's the IP address of the Modem and Router, if they're both the same then you'll have issues.

Modem should also be plugged into the WAN port of the router, and pc plugged into the LAN port of the router.

Modem should be in proper bridge mode, not dhcp mode.

Make sure you restart and boot up your modem first before turning on your router. You can't normally switch back and forth between direct wire of your PC and your router WAN port without rebooting the modem.
 
Jul 19, 2022
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My point is that the issue persists even when router and modem are not connected to each other. So
Socket A: modem
Socket B: router
No connection between the two of them. If I unplug the router, the issue is gone. If I connect any other decive to that socket B, the issue is back. It only takes a few seconds to appear in a game as packet loss/regular ping spikes after I plug anything in or out.

When I connect the router to the modem (yes, modem to router goes into wan) - again I don‘t even have to do that in order to reproduce the issue, I also charged my phone and plugged a speaker into the socket and had the same problems - the modem is in bridge mode and I access it through my router (192.168.10.1) - see https://openwrt.org/docs/guide-user/network/wan/access.modem.through.nat - under the address 192.168.1.1.

BUT AGAIN: As I found out today, this does not seem to be an issue with the network config because
A) the issue is gone when I plug the router into another socket,
B) the issue is even there when the PC is directly connected to the modem in bridge mode (not ideal, but tried it for testing purposes) and the router is doing nothing, meaning it is just plugged in but without any active connections, wifi turned off, settings were reset.
C) Any other electrical device that is hooked up to the faulty socket leads to the same issue. My problem is that I have to run this trough my landlord since I’m not allowed to call an electrician myself (legal regulation since the house is under monumental protection) and they had no clue what I was talking about when I mentioned that this socket causes network problems since they don‘t even have an internet connection themselves. So I need to know what kind of electrical interference - maybe one socket branches off from the other, maybe the cable to the socket runs too close to the telephone wires? - is likely behind this issue so that they actually call an electrician. There are not that many sockets in this apartment which is why it‘s rather important for us that we can use this one as well.
 
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gggplaya

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OOHHHH, you're talking about the POWER OUTLET. Socket is too broad of a term, it can mean multiple things and I was thinking you were talking about the ethernet port.

Zyxel is an extremely cheap router, and some of the things they cheap out on are the power circuits and noise filters for the circuits.

Are you sharing power with the other apartments, or do you have your own power panel?

Fluorescent lights and even some LED bulbs can cause interference, as do refrigerator compressors and washers and dryers.

Perhaps it isn't noise at all, but rather the breaker or outlet is corroded and not providing proper voltage or sinewave frequency. If you have a multimeter or can borrow one. I would check the outlet voltage to see if it's within specification for your country. In the U.S. it should be around 120v with a 5% tolerance at 60hz. In Europe I think it should be at 230v with a 6% tolerance at 50hz. My multimeter can test both frequency and AC voltage. But not all meters can test frequency.
 

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