What broadband do you need for VoIP?

The numbers

A single VoIP call uses roughly 100 kbps in each direction — trivial for any modern connection. Ten simultaneous calls still need only about 1 Mbps each way. If your broadband streams video, it can carry your phones.

What actually causes bad calls

• Jitter: packets arriving unevenly, heard as choppy audio
• Latency: delay that makes people talk over each other
• Packet loss: gaps and dropouts, often from overloaded wifi
• Cheap or overloaded routers struggling under load

Simple fixes

Put desk phones on a wired connection where possible, keep phones on a modern router, and prioritise voice traffic if your router supports it. In offices with heavy wifi use, a separate network for voice removes most complaints outright.