ps shared-medium Ether- net. But the Ethernet community did not stand still. Manufacturers (notably Cisco Systems) promoted Switched Ethernet, which took out the cable sharing. Then Fast Ethernet came out, at 100 Mbps, at a lower price than ATM. This turned out to be the death of ATM LANs. Although ATM could carry voice, data, or video, and assign flexible bandwidth and quality of service (QoS) to each user, most local area data users did not need those telecom-market features and were happy with cheaper Ethernet. ATM was pronounced dead, and B-ISDN did not resuscitate it. But ATM did not really die. It may have gone into hibernation, but it made a comeback as a backbone for Internet service providers, and then as part of the underlying technology in digital subscriber line services. A lot of ATM companies, however, did not survive. During the early B-ISDN era, another technology was posited as a short- term alternative. Frame Relay was, like X.25 and IP, based on variable-length frames; indeed it was created by taking X.25 and throwing away any function that could be performed outside of, rather than within, the network, and then some. The result was a lean, mean, simple data communications protocol, oper- ating within so-called Layer 2, that offered some QoS options while being The Great Telecom Meltdown designed to operate comfortably up to speeds of about 2 Mbps. It was also designed to interwork easily with ATM. Frame Relay was designed to be a tele- phone company service-its working title began as "ISDN New Packet Mode Bearer Service," but it was introduced to market by enterprise-network and long distance vendors. Wiltel brought its Wilpak service on line in 1991, using enterprise-grade Stratacom switches that were really little more than statistical multiplexors. Startup Cascade Communications and Northern Telecom were both major vendors of Frame Relay gear, which often could also support ATM. Ironically, it was AT&T Technologies that devoted the most effort to standard- izing Frame Relay, which was based