Throttling bandwidth on an IIS based site
If you need to throttle (or limit) the amount of bandwidth a specific site on Microsoft Server — this is for you. This should work with any Microsoft Server OS from 2008 to present. Open IIS. Go to the specific site in question (in the tree to left expand and click on the specific site name).
on the right side panel, click Configure — Limits.
Check “limit bandwidth usage” and type in a number.