A large ISP (DSL provider) in California sells *their* VoIP service.
If you order their VoIP service, all is well, quality is good, it works.
If you DO NOT order their VoIP service, they sabotage your VoIP packets, you cannot use their DSL for voice service (another provider, or build-your-own).
Basically, they implement a tiered service, or a $39 surcharge for the ability to use VoIP through their DSL.
What next? Perhaps a $39 surcharge if you want to use some other email service, or for watching YouTube, or for browsing OpenInternet.gov
Let's make the net neutral again!