Cable Buffer Bloat

Way back in 2012, I discovered and resolved a problem known as "Buffer Bloat" on my DSL connection. A simple tweak to the router's QoS settings resolved it.

Over the years, I had moved to cable connection with 800 Mbps download. Every now and them I still run across discussions of "Buffer Bloat".

Here's Google's AI explanation:

Bufferbloat is high network latency caused by routers or network equipment storing too many data packets in oversized queues during congestion.

What Causes It

• Oversized Buffers: Network devices hold onto data packets in first-in, first-out (FIFO) queues instead of dropping or prioritizing them.
• Link Saturation: Heavy background tasks like cloud backups, large downloads, or streaming fill up the queue.
• TCP Behavior: Transmission Control Protocol (TCP) continues to pump data into the pipeline, amplifying the queue delay.

Common Symptoms

• Lag Spikes: High ping or stuttering during online gaming, even when raw download speeds are fast.
• Poor Video/Audio Calls: Voice over IP (VoIP) or Zoom calls freeze, drop, or become distorted.
• Sluggish Browsing: Web pages stall when another device on the local network starts a heavy transfer.

I hadn't looked at this in almost 15 years so I dug into it again.

waveform.com has a quick test for "Buffer Bloat". Here's my result:

Since there was such a small difference in unloaded and upload active latency, I didn't do anything. If yours is different, you should go look at your router's Quality of Service settings. Google for your router and QoS for settings.