Specifies a media- level, point-to-point, 12-channel, full-duplex, electrical/optical interface, with each channel operating at 500 Mbit/s or 1 Gbit/s. Multimode (MM) fiber cables, and single-mode (SM) fiber cables, are used for distances up to 1 km when carrying the HIPPI-6400-PH protocol. Differential signals are used on the electrical side.