Network & QoS
VoIP Bandwidth Requirements
By Myroslav Orshak · operates licensed carrier infrastructure · Updated September 2026
A business VoIP call uses roughly 87 kbps in each direction on the standard G.711 codec, meaning even a dozen simultaneous calls fit comfortably inside 1 Mbps — a small fraction of any modern business connection.
How it works
The voice itself is only part of the traffic. A call sends 50 packets per second — one every 20 milliseconds — and each carries 160 bytes of audio wrapped in 58 bytes of addressing: IP, UDP, RTP, and Ethernet framing. That overhead is why a 64 kbps voice stream needs about 87 kbps of network capacity, with more than a third of the total being envelope rather than letter.
It also explains why compressed codecs save less than they appear to. G.729 squeezes the audio from 64 kbps down to 8, but the packet headers do not shrink at all — so the real saving is 87 kbps down to 31, not 64 down to 8.
Why it matters
Because bandwidth is the wrong thing to worry about, and worrying about it costs businesses money. A ten-person office rarely has more than three or four calls running at once — about 350 kbps of voice traffic, a rounding error on a connection sold in hundreds of megabits. Upgrading your internet plan to fix call quality is one of the most common wasted purchases in small business technology.
What actually determines quality on a connection that already has capacity is steadiness: whether packets arrive on time, evenly, and in order. That is why our tools measure loss and jitter rather than speed, and why the fix for bad calls is usually a router setting or a cable, not a bigger plan.
Including IP, UDP, RTP and Ethernet overhead at the standard 20 ms packet interval: G.711 and G.722 need 87.2 kbps per call each way, Opus at a typical 24 kbps setting about 47.2 kbps, and G.729 about 31.2 kbps.
Related terms
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Calculate what your office needs →Frequently asked questions
How much bandwidth do I need for 10 VoIP phones?
Far less than having ten phones suggests, because they are not all in use at once. A normal office peaks at about 30% concurrency — three or four simultaneous calls, roughly 350 kbps. Double that for headroom and you need under 1 Mbps. A sales floor where everyone is on the phone continuously would need about 900 kbps, still under 2 Mbps with headroom.
Do I need faster internet for VoIP?
Almost certainly not. If you already have a modern business connection, you have many times the capacity voice requires. Buying more speed does not fix calls that sound bad, because the problem is nearly always packet timing rather than throughput. Test your connection's steadiness before spending anything.
How much upload speed does VoIP need?
The same as download — voice is symmetric, since you are sending and receiving simultaneously. This matters on older cable and DSL connections where upload is a fraction of download: it is the upload figure that constrains how many calls you can run, and the one worth checking.
Should I use a compressed codec to save bandwidth?
Rarely worth it now. G.729 saves about 56 kbps per call against G.711 and costs you audible audio quality. On any connection with capacity to spare — which is most — take the better-sounding codec. Compression earns its place on genuinely constrained links, such as a remote site on limited connectivity.