At 16 users I would expect this. For example if just a couple users are watching video content all others may suffer. Of if the others are downloading big files.
With only DSL and that many users they will have to learn to tap the web lightly.
I think my network may have an issue with contention. It's only a small network servicing about 16 client machines but we keep getting timeouts as we use the web. The ADSL line has been tested and the router, switch, filter, and wiring have all been changed but we still have the problem.
Does anyone know how I can test to see if it is contention or have any advice as to what it might be?