I'm struggling with packet loss, possibly due to QoS problems.
I'm struggling with packet loss, possibly due to QoS problems.
Hey everyone, I’m facing a strange packet loss problem in my new German apartment. My setup uses a Fritzbox 7530AX as the modem: LAN1 connects to my gaming PC, LAN2 links to the second-floor router, and LAN3 goes to the first-floor router. The connection runs at 100MBit/s down and 40MBit/s up via VDSL/Vectoring. I’m seeing heavy packet loss in games like Valorant, Overwatch 2, and CS2 whenever another device—whether it’s a TV on LAN4 or a phone over Wi-Fi—uses even a tiny bit of bandwidth.
I’ve tried several fixes: swapped the modem with a Fritzbox 7590, reset all devices after factory settings, changed firmware versions, adjusted QoS settings, used different cables, switched power supplies and motherboards, and even disabled fuses one by one. The only time I got rid of the issue was when I turned off Wi-Fi completely except for my gaming PC.
I noticed this could be related to bufferbloat, which I remember from a previous setup with OpenWRT. Now I’m switching back to Fritzbox hardware to get better coverage across the apartment. Any suggestions on what else I could try?
The 100MB download and 40MB upload speeds seem average; it might be a bandwidth problem. Are you connecting your gaming PC directly to the modem or the router? If it's the modem, try connecting it to the router. Also check for packet loss using WiFi instead of a hardwired connection.
It’s true – it’s not very fast, but it still meets the average internet speed in Germany. The connection quality is poor, especially with fiber not being available everywhere. During gaming, my speeds are around 15Mbit/s down and 3Mbit/s up at most. I’ve tested both modem and router configurations, swapped devices, used different PCs, and even ran pingplotter on various machines. All connections via Wi-Fi or LAN show the same issue: any slight increase in bandwidth causes packet loss across the network. When this happens, performance drops to the stated limits (15/3).