VoIP-Sol.com drops ten names of ISPs or Countries blocking VoIP with a fair bit of detail for each. It looks reasonably accurate. The short version?
- PanamaBelizeCaribbeanClearwire (USA)Madison River (USA)Telmex (Mexico)BrazilUAEChina (China gets #9 and #10 on the list)
They suggest a service called Bound-IP (an apoplication that runs on a Windows PC) as a work-around, at least for software VoIP applications running on that PC, but looking at that software/service, it doesn’t look like Bound-IP would be very difficult to block either. It might work for a while, but if it gets popular as a work-around, these same ISPs/Countries could probably also block Bound-IP pretty easily.