The present invention relates to cables made of twisted conductor pairs. More specifically, the present invention relates to twisted pair communication cables for high-speed data communications applications. A twisted pair including at least two conductors extends along a generally longitudinal axis, with an insulation surrounding each of the conductors. The conductors are twisted generally longitudinally along the axis. A cable includes at least two twisted pairs and a filler. At least two of the cables are positioned along generally parallel axes for at least a predefined distance. The cables are configured to efficiently and accurately propagate high-speed data signals by, among other functions, limiting at least a subset of the following: impedance deviations, signal attenuation, and alien crosstalk along the predefined distance.