Router QoS for games, and when it does nothing

What QoS does

Your router sends everything from your home through one internet line. When a download, a video call and your game all want the line at once, packets wait their turn in the router. TP-Link's QoS guide describes the setting as giving chosen devices or kinds of traffic, such as gaming, more of the bandwidth when the network is busy.

The small packets of a game then skip the queue. While the line has room to spare, nothing waits, and QoS has nothing to reorder.

When QoS helps

• Someone in the house downloads a game update, streams video in high quality or uploads a backup while you play.
• The spread on the region you play on climbs over 20 ms, or requests get lost, while that traffic runs, and settles when it stops.
• The result reads Close but unstable on every region at once. Riot's troubleshooting guide names HD video streams, torrent programs and active Steam downloads among the programs that add packet buffering to a game connection.

When QoS does nothing

• Far from the servers and Cross region. That time builds up on the long way from your provider to the server, after the packet has left your router. QoS orders traffic inside your router only.
• An unstable result on weak Wi-Fi. QoS sorts the queue; it does not make a radio signal stronger. A cable or the 5 GHz band does.
• An unstable result while nobody else uses the line. With no other traffic, there is no queue to sort, and the cause sits elsewhere.

Set it up

1. Open your router's app or admin page and find the QoS section. Router makers use different names for it; TP-Link offers application priority and device priority.
2. Enter your line's real speed as the total bandwidth. TP-Link's routers fill in their own speed test result by default, and you can type your plan's figure instead. The router divides the line by this figure, so a wrong one leaves the queue where it was.
3. Give your gaming device, or the gaming category, the highest priority.

Check whether QoS helps on your line

1. Run the test while nobody else uses the internet. Note the spread on your region.
2. Start a large download on another device, with QoS off, and run the test again.
3. Turn QoS on with your device first and run it once more while the same download runs.

When the second run is worse than the first and the third comes back close to the first, QoS is doing its job. When the second run already matches the first, your line has room to spare, and the instability you saw before comes from somewhere else.