I’m looking for a company in the US that has moved a large number minutes of on-to-on traffic from a carrier VPN to their IP backbone. I’m not looking for a company doing voice to a small branch or a mobile worker via DSL. I’m looking for voice over their IP backbone between locations with 500 or so people. Voice that was carried on a bundled VPN. I’m also looking for a company that has had success with audioconferencing via IP.