What Is Bufferbloat?

Bufferbloat is excessive queuing (buffering) of packets in your modem/router or along the path to the internet. When the line is busy (downloads/uploads), packets sit in oversized buffers, inflating latency and jitter. Games, calls, and streams feel laggy or choppy even if your speed test looks “fast.”

How it shows up

Good idle ping, terrible under load: e.g., 20 ms idle → 200+ ms while downloading.
Inconsistent game feel: delayed hit‑reg, rubber‑banding, missed inputs.
Call/video issues: talk‑over, freezes, audio dropouts.

Why it happens

Traditional gear tries to avoid packet loss by buffering “too much.” When multiple devices upload or download, those big queues fill up. The result: packets wait their turn, and your real‑time traffic (game/VoIP) waits behind bulk transfers.

The modern fix: SQM (Cake / FQ‑Codel)

Smart Queue Management (SQM) actively controls queue length and fairly schedules flows so real‑time packets aren’t trapped behind large transfers.

FQ‑Codel: Fair Queuing + CoDel (delay control). Great default.
Cake: Newer, integrates shaping + fairness; often simpler and more robust.

Quick win checklist

Run our test and note your idle vs. loaded latency and jitter.
Enable SQM on your router (Cake or FQ‑Codel) and set upload/download shaper slightly below your real line rate (e.g., 90–95%).
Re‑run the test. You should see a better bufferbloat grade and much lower spikes under load.

When to upgrade hardware

If your current gateway doesn’t offer SQM or can’t keep up at your plan speed, consider a router that supports Cake/FQ‑Codel and has strong CPU for shaping.