IPerf just works between any two machines running IPerf. One attempts to read and write large files to/from the other and the speed is measured between the two. This is likely to be the underlying testing method used in a product like domotz or ovrc. This means you can run it between a couple of laptops on a local network to test wired and/or wireless speeds or you can run it on a cloud vm and use it to test internet speeds. Beware that you can chew through masses of bandwidth on a metered connection.