Fast Ethernet developments continue apace with the announcement that Grand Junction Networks Inc, SynOptics Communications, Sun Microsystems Computer Corp, National Semiconductor Corp presumably wanting to make the chips – and un-named others are developing a 100Base-X interoperability specification based on Union City, California-based Grand Junction’s proposal to the IEEE 802.3 committee last November. The companies are part of the faction that backs keeping Ethernet’s CSMA/CD protocol more-or-less unadulterated for the 100Mbps version of the dominant networking standard. 100Base-X glues CSMA/CD onto the ANSI X3T9.5 Physical Medium Dependent layer used by copper-based Fibre Distributed Data Interface. Unfortunately this technology is limited to category 5 (data grade) unshielded twisted pair cabling, whereas the broader coalition of CSMA/CD supporters are pushing for support on voice grade category 3 and 4 cabling as well. It is understood that 3Com Corp will be giving some form of definitive word on its plans on August 2.
