High Speed Token Ring (HSTR) is a 100Mbps implementation of Dedicated Token Ring. In fact, its official title is 100Mbps Dedicated Token Ring. Combination 4/16/100Mbps NICs and matching Concentrators/Switches have been available for several years.
The HSTR physical coding and transmission specification was adopted directly from CDDI and FDDI, as were 100BASE-TX and 100BASE-FX Ethernet. The copper implementation runs across two pairs of Category 5 unshielded twisted-pair cabling or two pairs of IBM Type 1 shielded twisted–pair cabling. The fiber optic implementation runs on a pair of multimode fibers. Fiber optic lobes can be used.
A 4B/5B encoding is used for both copper and fiber optic cables. Appendix A has the ...