What are the bandwidth requirements for VoIP phone systems?

For audio calls, very minimal bandwidth is required which most of the broadband connection providers are providing around the world. From our experience of providing cloud phone system solution to 1000s of businesses around the world, 100 kbps is more than enough for a single call so if your team is doing 20 simultaneous calls, anything above 2 Mbps will do.

But, having said that, bandwidth alone is not responsible for ensuring call quality. What really matters is consistency of packet transfer. On your network, there are numerous other applications running which consume bandwidth in random manner so you have to use QOS settings of your router to ensure your calling application is getting consistent bandwidth.

To explain you this, check this diagram below:

Without QOS, you can see Audio Call was not getting consistent bandwidth hence it was causing Jitter, Latency and Call Drop.

But, after ensuring that IPs related to calling were granted set minimum bandwidth, the consistent bandwidth availability, improved call quality.

Here is a short article we wrote on Factors that affect Call Quality to understand different other factors affecting your VoIP Call Quality.