1-pair, cannot share with voice. 1 pair, to 4,500 feet. A symetrical version of VDSL does 26-mbps both directions. 1-pair, to 4,500 feet. Any of the above.
Multiplexing allows several carrier streams to simultaneously use the same fiber.
In most cases each of these streams will be multiplexed to carry a number of simultaneous voice or data streams. Frame Relay - A telecomunications protocol for economical transport of digital material. It is used for transmission between two sites on a LAN, or from a LAN into the Internet. Frame can run over various transmission media. Over high speed media, Frame Relay can simultaneously carry both voice and data communications.