G.711 Codec: What It Is, Why It Matters for VoIP Call Quality

When you make a VoIP call, the sound of your voice gets turned into digital data using something called a G.711, a standard audio codec used to encode voice signals in digital telephony systems. Also known as PCMU or PCMA, it’s the most basic but often the clearest way to send voice over the internet. Unlike modern codecs that compress audio to save bandwidth, G.711 keeps voice almost exactly as it sounds in real life—no tricks, no cuts. That’s why it’s still the go-to for businesses that need crystal-clear calls, like call centers, hospitals, and legal firms.

G.711 doesn’t try to be smart about saving space. It uses 64 kbps per call, which is twice as much as G.729. That might sound like a lot, but if your internet connection is solid and you’re not running hundreds of calls at once, the trade-off is worth it. You get natural-sounding voice, zero lag, and no robotic artifacts. Compare that to G.729, which compresses voice so hard it sometimes sounds like you’re talking through a tin can. G.711 doesn’t have that problem. It’s why many VoIP providers still offer it as a default option—even when they push you toward lighter codecs.

But bandwidth isn’t the only thing that matters. G.711 works best when your network has low jitter and stable routing. If your ISP doesn’t prioritize voice traffic, even G.711 can sound choppy. That’s why it’s often paired with QoS settings and UDP protocols—both of which show up in other posts on this site. You’ll also see how G.711 affects power usage, since higher bandwidth means more data flowing, which can strain older hardware. And if you’re connecting analog phones via FXS ports, G.711 is usually the default codec because it matches the analog signal perfectly.

It’s not the future, but it’s still the present. G.711 is the benchmark everyone else is measured against. Whether you’re setting up a FreePBX system, choosing a VoIP provider, or troubleshooting echo on your Cisco phone, understanding G.711 helps you make smarter decisions. Below, you’ll find real-world comparisons, bandwidth calculators, and setup guides that show exactly how G.711 stacks up against the alternatives—and when you should stick with it.