Planning bandwidth for a growing network

8 min read

How much upstream capacity do you actually need? A simple model gets you most of the way.

Contention

Not everyone uses their full speed at the same time. The contention ratio says how many subscribers share each unit of capacity. A ratio of 20:1 means twenty subscribers share what one could use alone.

A simple formula

capacity = subscribers x plan speed / contention ratio

For 300 subscribers on 20 Mbps plans at 20:1, that is 300 x 20 / 20 = 300 Mbps.

Peaks matter more than averages

Evenings and weekends set your real need. Plan for them, not for the quiet hours.

Watch utilisation

When your busiest hour regularly uses most of your capacity, it is time to add more. Do not wait for complaints.

Try the bandwidth planner with your own numbers.