Network Speed Testing and Monitoring Platform

As an internet service provider with many small business and residential customers, our most common tech support calls are speed related. Customers complaining on slow speeds, slowdowns, etc. We have a SNMP and ping monitoring platform today, but that mainly tells us up-time and if data is flowing across the interface. We can of course see the link speed, but customer call in saying the are not getting that speed. We are looking for a way to remotely test customers internet connections besides telling the customer to go to speedtest.net, or worse sending a tech out with a laptop to do the same thing. What opensource and commercial options are out there?