Eons ago I worked at WDNC in Durham NC. They originated the Duke University sports network. For away games they used a single dial-up phone line and couplers. Years later I worked at MBS/NBC and they used two-line Comrexes, then Switched-56 and ISDN where it was available. When I worked for Radio Marti we would use ISDN and then AoIP with Comex Rack and BrickLinks. What are stations using now to do the backhauls?