Provided are inorganic fibers containing calcium and alumina as the major fiber components. The RGB image data are converted into the luminance Y and the chromaticity values C1, C2, then a highlight point and a shadow point are determined and are connected to define the axis of the color solid. During the initial signaling process for the communication session, the nodes seeking the communication session include the SPIs in the signaling messages and send the signaling messages through the monitoring intermediary which in turn matches the SPIs of the signaling messages with the corresponding SPIs extracted from the data packets.