There are examples for this, eg carrier IPTV. 3GPP IMS had the grand vision of telco-controlled Internet Multimedia System (IMS), an Internet modeled after the

There are examples for this, eg carrier IPTV. 3GPP IMS had the grand vision of telco-controlled Internet Multimedia System (IMS), an Internet modeled after the phone network. It runs over separate lines or at least separate layer 2 sessions. An application would use a signaling protocol (SIP etc) to request access to "multimedia" services like gaming, the telco would reserve bandwidth and guarantee that the service could be accessed with assured quality (and billed, of course). While IMS uses internet tech, it has a completely different philosophy. I'm not aware of any IMS network that went beyond doing telephony, though.