A connector includes a first layer having first and second communication channels, and a ground channel. The first and second communication channels form a first differential pair and transmit a differential signal. The ground channel separates the first differential pair from a next differential pair within the first layer. A surface of the ground channel nearest the first and second communication channels is selectively roughened to a particular roughness level to dampen crosstalk between the first differential pair and the next differential pair to a particular crosstalk level.