Contention/Oversubscription maths

Fri May 27 14:49:45 UTC 2011

I run a WISP, where we have moved customers from 3mb/s to 8mb/s to 20mb/s
over the course of 5 years. We do this one tower at a time (about 150
customers) what we have learned is usage grows overtime not with the
increase in available bandwidth.  Our Per-Customer-Avg (PCA) stayed about
the same with each bump in bandwidth, the avg user does not use more
bandwidth because they have more bandwidth or at least not our 1200
customers.

That said we have had our PCA move up more then 30% in the last 7 months due
mainly to Netflix, the nice thing is this usage is "off peak" for
our business customers and as such has not been a concern.

Shaun

Shaun Bryant
sbryant at thepit.org