An automated patch-panel system for fiber optic networks, the system being responsive to signal commands for reconfiguration of system interconnections between first and second networks and comprising: a two dimensional input array of dual ended terminals accessible to input optical lines from a first network on one side thereof, the input terminals being disposed in at least one dimension in a first plane with spaces between the terminals on a second side opposite the side of the first network, said second side defining one boundary of an interconnection volume; a plurality of optical fiber lines removably coupled to the individual terminals of the input array at said one boundary and extending into the interconnection volume; a second, one dimensional intermediate array of coupling elements in a plane spaced apart from the second side of the input array and defining a backbone arrangement adjacent the intervening interconnection volume for collecting optical fiber lines from the input array in predetermined converging sets, the sets being disposed in the intermediate array at different levels relative to the input array; a number of variable length fiber buffers in modular form disposed at different levels adjacent the intermediate array; the buffers each coupling a different one of the number of fiber lines from the intermediate fiber line sets to a second network of the system, and compensating for length variations in the fibers by tensioning the fibers in the converging sets so that each of the fibers follows a straight path through said interconnection volume between said input array and said intermediate array while maintaining more than a minimum curvature therein; a controller having a database storing vector data as to existing fiber line interconnections within the interconnection volume for generating position commands, said vector data including, for each fiber line, a vector defining the three dimensional orientation of the fiber line through the interconnection volume and an automated positioner adjacent the first plane, the positioner including a fiber line engagement mechanism for transferring fiber lines from selected target locations to destination locations within the input array in response to position commands from the controller, wherein the controller generates position commands in response to the vector data in the database to drive the engagement mechanism selectively through existing interconnections dependent on their local vectors that any selected one of the fiber lines that is moved from a selected target location to a destination location within the input array will be straight without interference from any of the other fiber lines in the interconnection volume when the selected one of the fiber lines is reconnected to the destination location. a two dimensional input array of dual ended terminals accessible to input optical lines from a first network on one side thereof, the input terminals being disposed in at least one dimension in a first plane with spaces between the terminals on a second side opposite the side of the first network, said second side defining one boundary of an interconnection volume; a plurality of optical fiber lines removably coupled to the individual terminals of the input array at said one boundary and extending into the interconnection volume; a second, one dimensional intermediate array of coupling elements in a plane spaced apart from the second side of the input array and defining a backbone arrangement adjacent the intervening interconnection volume for collecting optical fiber lines from the input array in predetermined converging sets, the sets being disposed in the intermediate array at different levels relative to the input array; a number of variable length fiber buffers in modular form disposed at different levels adjacent the intermediate array; the buffers each coupling a different one of the number of fiber lines from the intermediate fiber line sets to a second network of the system, and compensating for length variations in the fibers by tensioning the fibers in the converging sets so that each of the fibers follows a straight path through said interconnection volume between said input array and said intermediate array while maintaining more than a minimum curvature therein; a controller having a database storing vector data as to existing fiber line interconnections within the interconnection volume for generating position commands, said vector data including, for each fiber line, a vector defining the three dimensional orientation of the fiber line through the interconnection volume and an automated positioner adjacent the first plane, the positioner including a fiber line engagement mechanism for transferring fiber lines from selected target locations to destination locations within the input array in response to position commands from the controller, wherein the controller generates position commands in response to the vector data in the database to drive the engagement mechanism selectively through existing interconnections dependent on their local vectors that any selected one of the fiber lines that is moved from a selected target location to a destination location within the input array will be straight without interference from any of the other fiber lines in the interconnection volume when the selected one of the fiber lines is reconnected to the destination location.